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GNU GENERAL PUBLIC LICENSE
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Version 3, 29 June 2007
|
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|
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Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
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Everyone is permitted to copy and distribute verbatim copies
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of this license document, but changing it is not allowed.
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Preamble
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|
||||
The GNU General Public License is a free, copyleft license for
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software and other kinds of works.
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|
||||
The licenses for most software and other practical works are designed
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to take away your freedom to share and change the works. By contrast,
|
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the GNU General Public License is intended to guarantee your freedom to
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share and change all versions of a program--to make sure it remains free
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software for all its users. We, the Free Software Foundation, use the
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GNU General Public License for most of our software; it applies also to
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any other work released this way by its authors. You can apply it to
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your programs, too.
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|
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When we speak of free software, we are referring to freedom, not
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have the freedom to distribute copies of free software (and charge for
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To protect your rights, we need to prevent others from denying you
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Finally, every program is threatened constantly by software patents.
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The precise terms and conditions for copying, distribution and
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TERMS AND CONDITIONS
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0. Definitions.
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"This License" refers to version 3 of the GNU General Public License.
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"Copyright" also means copyright-like laws that apply to other kinds of
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The Corresponding Source need not include anything that users
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The Corresponding Source for a work in source code form is that
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||||
All rights granted under this License are granted for the term of
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||||
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|
||||
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||||
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|
||||
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You may make, run and propagate covered works that you do not
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Conveying under any other circumstances is permitted solely under
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No covered work shall be deemed part of an effective technological
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||||
When you convey a covered work, you waive any legal power to forbid
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||||
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||||
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|
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||||
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||||
You may convey verbatim copies of the Program's source code as you
|
||||
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||||
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||||
keep intact all notices of the absence of any warranty; and give all
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You may charge any price or no price for each copy that you convey,
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||||
You may convey a work based on the Program, or the modifications to
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||||
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|
||||
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|
||||
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||||
|
||||
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|
||||
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|
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|
||||
"keep intact all notices".
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||||
|
||||
c) You must license the entire work, as a whole, under this
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||||
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||||
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||||
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|
||||
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||||
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||||
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|
||||
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||||
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|
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A compilation of a covered work with other separate and independent
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||||
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|
||||
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|
||||
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|
||||
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||||
|
||||
6. Conveying Non-Source Forms.
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||||
|
||||
You may convey a covered work in object code form under the terms
|
||||
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|
||||
machine-readable Corresponding Source under the terms of this License,
|
||||
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||||
|
||||
a) Convey the object code in, or embodied in, a physical product
|
||||
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|
||||
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||||
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||||
b) Convey the object code in, or embodied in, a physical product
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|
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written offer, valid for at least three years and valid for as
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||||
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|
||||
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|
||||
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|
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||||
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||||
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||||
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|
||||
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|
||||
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|
||||
may be on a different server (operated by you or a third party)
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||||
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||||
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||||
|
||||
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|
||||
you inform other peers where the object code and Corresponding
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Source of the work are being offered to the general public at no
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||||
|
||||
A separable portion of the object code, whose source code is excluded
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||||
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|
||||
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||||
|
||||
A "User Product" is either (1) a "consumer product", which means any
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||||
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||||
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||||
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commercial, industrial or non-consumer uses, unless such uses represent
|
||||
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|
||||
"Installation Information" for a User Product means any methods,
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||||
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|
||||
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|
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|
||||
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|
||||
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|
||||
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|
||||
If you convey an object code work under this section in, or with, or
|
||||
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|
||||
part of a transaction in which the right of possession and use of the
|
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|
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|
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Corresponding Source conveyed under this section must be accompanied
|
||||
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|
||||
if neither you nor any third party retains the ability to install
|
||||
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|
||||
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||||
|
||||
The requirement to provide Installation Information does not include a
|
||||
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|
||||
for a work that has been modified or installed by the recipient, or for
|
||||
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|
||||
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|
||||
adversely affects the operation of the network or violates the rules and
|
||||
protocols for communication across the network.
|
||||
|
||||
Corresponding Source conveyed, and Installation Information provided,
|
||||
in accord with this section must be in a format that is publicly
|
||||
documented (and with an implementation available to the public in
|
||||
source code form), and must require no special password or key for
|
||||
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|
||||
|
||||
7. Additional Terms.
|
||||
|
||||
"Additional permissions" are terms that supplement the terms of this
|
||||
License by making exceptions from one or more of its conditions.
|
||||
Additional permissions that are applicable to the entire Program shall
|
||||
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|
||||
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|
||||
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|
||||
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|
||||
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|
||||
|
||||
When you convey a copy of a covered work, you may at your option
|
||||
remove any additional permissions from that copy, or from any part of
|
||||
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|
||||
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|
||||
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|
||||
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||||
|
||||
Notwithstanding any other provision of this License, for material you
|
||||
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|
||||
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|
||||
|
||||
a) Disclaiming warranty or limiting liability differently from the
|
||||
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|
||||
|
||||
b) Requiring preservation of specified reasonable legal notices or
|
||||
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|
||||
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|
||||
|
||||
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|
||||
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|
||||
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||||
|
||||
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|
||||
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|
||||
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|
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||||
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||||
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|
||||
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|
||||
All other non-permissive additional terms are considered "further
|
||||
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|
||||
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|
||||
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|
||||
restriction, you may remove that term. If a license document contains
|
||||
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|
||||
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|
||||
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|
||||
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||||
If you add terms to a covered work in accord with this section, you
|
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|
||||
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|
||||
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|
||||
|
||||
Additional terms, permissive or non-permissive, may be stated in the
|
||||
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|
||||
the above requirements apply either way.
|
||||
|
||||
8. Termination.
|
||||
|
||||
You may not propagate or modify a covered work except as expressly
|
||||
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|
||||
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|
||||
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|
||||
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|
||||
|
||||
However, if you cease all violation of this License, then your
|
||||
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|
||||
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|
||||
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|
||||
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|
||||
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|
||||
|
||||
Moreover, your license from a particular copyright holder is
|
||||
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|
||||
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|
||||
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|
||||
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|
||||
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|
||||
|
||||
Termination of your rights under this section does not terminate the
|
||||
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||||
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|
||||
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|
||||
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|
||||
|
||||
9. Acceptance Not Required for Having Copies.
|
||||
|
||||
You are not required to accept this License in order to receive or
|
||||
run a copy of the Program. Ancillary propagation of a covered work
|
||||
occurring solely as a consequence of using peer-to-peer transmission
|
||||
to receive a copy likewise does not require acceptance. However,
|
||||
nothing other than this License grants you permission to propagate or
|
||||
modify any covered work. These actions infringe copyright if you do
|
||||
not accept this License. Therefore, by modifying or propagating a
|
||||
covered work, you indicate your acceptance of this License to do so.
|
||||
|
||||
10. Automatic Licensing of Downstream Recipients.
|
||||
|
||||
Each time you convey a covered work, the recipient automatically
|
||||
receives a license from the original licensors, to run, modify and
|
||||
propagate that work, subject to this License. You are not responsible
|
||||
for enforcing compliance by third parties with this License.
|
||||
|
||||
An "entity transaction" is a transaction transferring control of an
|
||||
organization, or substantially all assets of one, or subdividing an
|
||||
organization, or merging organizations. If propagation of a covered
|
||||
work results from an entity transaction, each party to that
|
||||
transaction who receives a copy of the work also receives whatever
|
||||
licenses to the work the party's predecessor in interest had or could
|
||||
give under the previous paragraph, plus a right to possession of the
|
||||
Corresponding Source of the work from the predecessor in interest, if
|
||||
the predecessor has it or can get it with reasonable efforts.
|
||||
|
||||
You may not impose any further restrictions on the exercise of the
|
||||
rights granted or affirmed under this License. For example, you may
|
||||
not impose a license fee, royalty, or other charge for exercise of
|
||||
rights granted under this License, and you may not initiate litigation
|
||||
(including a cross-claim or counterclaim in a lawsuit) alleging that
|
||||
any patent claim is infringed by making, using, selling, offering for
|
||||
sale, or importing the Program or any portion of it.
|
||||
|
||||
11. Patents.
|
||||
|
||||
A "contributor" is a copyright holder who authorizes use under this
|
||||
License of the Program or a work on which the Program is based. The
|
||||
work thus licensed is called the contributor's "contributor version".
|
||||
|
||||
A contributor's "essential patent claims" are all patent claims
|
||||
owned or controlled by the contributor, whether already acquired or
|
||||
hereafter acquired, that would be infringed by some manner, permitted
|
||||
by this License, of making, using, or selling its contributor version,
|
||||
but do not include claims that would be infringed only as a
|
||||
consequence of further modification of the contributor version. For
|
||||
purposes of this definition, "control" includes the right to grant
|
||||
patent sublicenses in a manner consistent with the requirements of
|
||||
this License.
|
||||
|
||||
Each contributor grants you a non-exclusive, worldwide, royalty-free
|
||||
patent license under the contributor's essential patent claims, to
|
||||
make, use, sell, offer for sale, import and otherwise run, modify and
|
||||
propagate the contents of its contributor version.
|
||||
|
||||
In the following three paragraphs, a "patent license" is any express
|
||||
agreement or commitment, however denominated, not to enforce a patent
|
||||
(such as an express permission to practice a patent or covenant not to
|
||||
sue for patent infringement). To "grant" such a patent license to a
|
||||
party means to make such an agreement or commitment not to enforce a
|
||||
patent against the party.
|
||||
|
||||
If you convey a covered work, knowingly relying on a patent license,
|
||||
and the Corresponding Source of the work is not available for anyone
|
||||
to copy, free of charge and under the terms of this License, through a
|
||||
publicly available network server or other readily accessible means,
|
||||
then you must either (1) cause the Corresponding Source to be so
|
||||
available, or (2) arrange to deprive yourself of the benefit of the
|
||||
patent license for this particular work, or (3) arrange, in a manner
|
||||
consistent with the requirements of this License, to extend the patent
|
||||
license to downstream recipients. "Knowingly relying" means you have
|
||||
actual knowledge that, but for the patent license, your conveying the
|
||||
covered work in a country, or your recipient's use of the covered work
|
||||
in a country, would infringe one or more identifiable patents in that
|
||||
country that you have reason to believe are valid.
|
||||
|
||||
If, pursuant to or in connection with a single transaction or
|
||||
arrangement, you convey, or propagate by procuring conveyance of, a
|
||||
covered work, and grant a patent license to some of the parties
|
||||
receiving the covered work authorizing them to use, propagate, modify
|
||||
or convey a specific copy of the covered work, then the patent license
|
||||
you grant is automatically extended to all recipients of the covered
|
||||
work and works based on it.
|
||||
|
||||
A patent license is "discriminatory" if it does not include within
|
||||
the scope of its coverage, prohibits the exercise of, or is
|
||||
conditioned on the non-exercise of one or more of the rights that are
|
||||
specifically granted under this License. You may not convey a covered
|
||||
work if you are a party to an arrangement with a third party that is
|
||||
in the business of distributing software, under which you make payment
|
||||
to the third party based on the extent of your activity of conveying
|
||||
the work, and under which the third party grants, to any of the
|
||||
parties who would receive the covered work from you, a discriminatory
|
||||
patent license (a) in connection with copies of the covered work
|
||||
conveyed by you (or copies made from those copies), or (b) primarily
|
||||
for and in connection with specific products or compilations that
|
||||
contain the covered work, unless you entered into that arrangement,
|
||||
or that patent license was granted, prior to 28 March 2007.
|
||||
|
||||
Nothing in this License shall be construed as excluding or limiting
|
||||
any implied license or other defenses to infringement that may
|
||||
otherwise be available to you under applicable patent law.
|
||||
|
||||
12. No Surrender of Others' Freedom.
|
||||
|
||||
If conditions are imposed on you (whether by court order, agreement or
|
||||
otherwise) that contradict the conditions of this License, they do not
|
||||
excuse you from the conditions of this License. If you cannot convey a
|
||||
covered work so as to satisfy simultaneously your obligations under this
|
||||
License and any other pertinent obligations, then as a consequence you may
|
||||
not convey it at all. For example, if you agree to terms that obligate you
|
||||
to collect a royalty for further conveying from those to whom you convey
|
||||
the Program, the only way you could satisfy both those terms and this
|
||||
License would be to refrain entirely from conveying the Program.
|
||||
|
||||
13. Use with the GNU Affero General Public License.
|
||||
|
||||
Notwithstanding any other provision of this License, you have
|
||||
permission to link or combine any covered work with a work licensed
|
||||
under version 3 of the GNU Affero General Public License into a single
|
||||
combined work, and to convey the resulting work. The terms of this
|
||||
License will continue to apply to the part which is the covered work,
|
||||
but the special requirements of the GNU Affero General Public License,
|
||||
section 13, concerning interaction through a network will apply to the
|
||||
combination as such.
|
||||
|
||||
14. Revised Versions of this License.
|
||||
|
||||
The Free Software Foundation may publish revised and/or new versions of
|
||||
the GNU General Public License from time to time. Such new versions will
|
||||
be similar in spirit to the present version, but may differ in detail to
|
||||
address new problems or concerns.
|
||||
|
||||
Each version is given a distinguishing version number. If the
|
||||
Program specifies that a certain numbered version of the GNU General
|
||||
Public License "or any later version" applies to it, you have the
|
||||
option of following the terms and conditions either of that numbered
|
||||
version or of any later version published by the Free Software
|
||||
Foundation. If the Program does not specify a version number of the
|
||||
GNU General Public License, you may choose any version ever published
|
||||
by the Free Software Foundation.
|
||||
|
||||
If the Program specifies that a proxy can decide which future
|
||||
versions of the GNU General Public License can be used, that proxy's
|
||||
public statement of acceptance of a version permanently authorizes you
|
||||
to choose that version for the Program.
|
||||
|
||||
Later license versions may give you additional or different
|
||||
permissions. However, no additional obligations are imposed on any
|
||||
author or copyright holder as a result of your choosing to follow a
|
||||
later version.
|
||||
|
||||
15. Disclaimer of Warranty.
|
||||
|
||||
THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
|
||||
APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
|
||||
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
|
||||
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
|
||||
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||||
PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
|
||||
IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
|
||||
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
|
||||
|
||||
16. Limitation of Liability.
|
||||
|
||||
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
|
||||
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
|
||||
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
|
||||
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
|
||||
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
|
||||
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
|
||||
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
|
||||
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
|
||||
SUCH DAMAGES.
|
||||
|
||||
17. Interpretation of Sections 15 and 16.
|
||||
|
||||
If the disclaimer of warranty and limitation of liability provided
|
||||
above cannot be given local legal effect according to their terms,
|
||||
reviewing courts shall apply local law that most closely approximates
|
||||
an absolute waiver of all civil liability in connection with the
|
||||
Program, unless a warranty or assumption of liability accompanies a
|
||||
copy of the Program in return for a fee.
|
||||
|
||||
END OF TERMS AND CONDITIONS
|
||||
|
||||
How to Apply These Terms to Your New Programs
|
||||
|
||||
If you develop a new program, and you want it to be of the greatest
|
||||
possible use to the public, the best way to achieve this is to make it
|
||||
free software which everyone can redistribute and change under these terms.
|
||||
|
||||
To do so, attach the following notices to the program. It is safest
|
||||
to attach them to the start of each source file to most effectively
|
||||
state the exclusion of warranty; and each file should have at least
|
||||
the "copyright" line and a pointer to where the full notice is found.
|
||||
|
||||
<one line to give the program's name and a brief idea of what it does.>
|
||||
Copyright (C) <year> <name of author>
|
||||
|
||||
This program is free software: you can redistribute it and/or modify
|
||||
it under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation, either version 3 of the License, or
|
||||
(at your option) any later version.
|
||||
|
||||
This program is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
|
||||
Also add information on how to contact you by electronic and paper mail.
|
||||
|
||||
If the program does terminal interaction, make it output a short
|
||||
notice like this when it starts in an interactive mode:
|
||||
|
||||
<program> Copyright (C) <year> <name of author>
|
||||
This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
|
||||
This is free software, and you are welcome to redistribute it
|
||||
under certain conditions; type `show c' for details.
|
||||
|
||||
The hypothetical commands `show w' and `show c' should show the appropriate
|
||||
parts of the General Public License. Of course, your program's commands
|
||||
might be different; for a GUI interface, you would use an "about box".
|
||||
|
||||
You should also get your employer (if you work as a programmer) or school,
|
||||
if any, to sign a "copyright disclaimer" for the program, if necessary.
|
||||
For more information on this, and how to apply and follow the GNU GPL, see
|
||||
<http://www.gnu.org/licenses/>.
|
||||
|
||||
The GNU General Public License does not permit incorporating your program
|
||||
into proprietary programs. If your program is a subroutine library, you
|
||||
may consider it more useful to permit linking proprietary applications with
|
||||
the library. If this is what you want to do, use the GNU Lesser General
|
||||
Public License instead of this License. But first, please read
|
||||
<http://www.gnu.org/philosophy/why-not-lgpl.html>.
|
|
@ -0,0 +1,89 @@
|
|||
Go-EBML
|
||||
=======
|
||||
A marshaler/unmarshaler for [EBML](http://ebml.sourceforge.net/).
|
||||
|
||||
It's quite simple to use:
|
||||
```go
|
||||
|
||||
func ExampleMarshal() {
|
||||
DoDad := new(struct {
|
||||
EbmlId ebml.Id `ebml:"3f0000"`
|
||||
DoHickey uint `ebml:"4242"`
|
||||
ThingaMabob string `ebml:"4243"`
|
||||
HumDinger int `ebml:"4244"`
|
||||
})
|
||||
|
||||
DoDad.DoHickey = 70000
|
||||
DoDad.ThingaMabob = "huzah"
|
||||
DoDad.HumDinger = -92387
|
||||
|
||||
b, _ := ebml.Marshal(*DoDad)
|
||||
fmt.Printf("0x%x\n", b)
|
||||
|
||||
// Output:
|
||||
// 0x3f00009442428301117042438568757a6168424483fe971d
|
||||
}
|
||||
|
||||
func ExampleUnmarshal() {
|
||||
data := []byte{
|
||||
0x3f, 0x00, 0x00, 0x94,
|
||||
0x42, 0x42, 0x83, 0x01, 0x11, 0x70,
|
||||
0x42, 0x43, 0x85, 0x68, 0x75, 0x7a, 0x61, 0x68,
|
||||
0x42, 0x44, 0x83, 0xfe, 0x97, 0x1d,
|
||||
}
|
||||
|
||||
DoDad := new(struct {
|
||||
EbmlId ebml.Id `ebml:"3f0000"`
|
||||
DoHickey uint `ebml:"4242"`
|
||||
ThingaMabob string `ebml:"4243"`
|
||||
HumDinger int `ebml:"4244"`
|
||||
})
|
||||
|
||||
ebml.Unmarshal(data, DoDad)
|
||||
fmt.Printf("%v\n", DoDad)
|
||||
// Output:
|
||||
// &{0 70000 huzah -92387}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
|
||||
Caveats
|
||||
-------
|
||||
If an EBML DTD specifies a value as an unsigned integer, you must use a uint
|
||||
type. For example: the uint32 8388608 and int -8388608 may encode to identical
|
||||
0x800000 24 bit arrays in an EBML stream.
|
||||
|
||||
EBML does not have a boolean type, but booleans are commonly defined in DTDs
|
||||
as zero or non-zero usigned integers.
|
||||
|
||||
|
||||
Not Implemented
|
||||
---------------
|
||||
* Default values.
|
||||
> Every non-container MAY be assigned a default value. If so, its
|
||||
> value will be added to the interpretation of the EBML data if no
|
||||
> element with another value exists in the data.
|
||||
>
|
||||
> As an example, consider this EBML DTD:
|
||||
>
|
||||
> Weight := 4101 {
|
||||
> WeightValue := 41a1 uint;
|
||||
> WeightUnit := 41a2 string [ def:"kilogram" ];
|
||||
> }
|
||||
>
|
||||
> If the Weight element only contains the WeightValue element, the
|
||||
> WeightUnit element with value "kilogram" will be added when the
|
||||
> information is semantically processed. A WeightUnit element with
|
||||
> another value would of course override the default.
|
||||
>
|
||||
> The default value can also be a symbol referring back to a
|
||||
> previously seen symbol. If however no such symbol has been seen,
|
||||
> i.e. it has not been encoded into the EBML data and has no default
|
||||
> value, the element will not be added as a child on the semantic
|
||||
> level.
|
||||
>
|
||||
> Weight := 4101 {
|
||||
> WeightValue := 41a1 uint;
|
||||
> WeightUnit := 41a2 string [ def:WeightUnit ];
|
||||
> }
|
|
@ -0,0 +1,110 @@
|
|||
// Copyright © 2013 Emery Hemingway
|
||||
// Released under the terms of the GNU Public License version 3
|
||||
|
||||
package ebml
|
||||
|
||||
import (
|
||||
"reflect"
|
||||
"sync"
|
||||
)
|
||||
|
||||
var (
|
||||
fieldIdMap = make(map[reflect.Type]map[Id]int)
|
||||
fieldIdMutex sync.RWMutex
|
||||
//fieldDecoderMap = make(map[reflect.Type][]decoderFunc)
|
||||
//fieldDecoderMutex sync.RWMutex
|
||||
)
|
||||
|
||||
// cachedFieldIdMap returns a map that contains Id to field number
|
||||
// mappings for typ
|
||||
func cachedFieldIdMap(typ reflect.Type) map[Id]int {
|
||||
fieldIdMutex.RLock()
|
||||
m, ok := fieldIdMap[typ]
|
||||
fieldIdMutex.RUnlock()
|
||||
if ok {
|
||||
return m
|
||||
}
|
||||
|
||||
// Didn't get a map, lock down the map
|
||||
fieldIdMutex.Lock()
|
||||
defer fieldIdMutex.Unlock()
|
||||
m, ok = fieldIdMap[typ]
|
||||
if ok { // the work is already done
|
||||
return m
|
||||
}
|
||||
|
||||
m = make(map[Id]int)
|
||||
// look over the fields
|
||||
for i := 0; i < typ.NumField(); i++ {
|
||||
f := typ.Field(i)
|
||||
if f.Name == "EbmlId" {
|
||||
continue
|
||||
}
|
||||
tag := f.Tag.Get("ebml")
|
||||
if tag == "" || tag == "-" {
|
||||
continue
|
||||
}
|
||||
id, err := NewIdFromString(tag)
|
||||
if err != nil {
|
||||
panic(ebmlError("ebml: could not parse Id from struct " + typ.String() + " field " + f.Name + ", " + err.Error()))
|
||||
}
|
||||
m[id] = i
|
||||
}
|
||||
fieldIdMap[typ] = m
|
||||
return m
|
||||
}
|
||||
|
||||
/*
|
||||
|
||||
// cachedFieldIpDecoderTable returns a slice that contains decoder functions
|
||||
// indexed by field number
|
||||
func cachedFieldDecoderTable(typ reflect.Type) []decoderFunc {
|
||||
fieldDecoderMutex.RLock()
|
||||
s, ok := fieldDecoderMap[typ]
|
||||
fieldDecoderMutex.RUnlock()
|
||||
if ok {
|
||||
return s
|
||||
}
|
||||
|
||||
// Didn't get a slice, lock down the map
|
||||
fieldDecoderMutex.Lock()
|
||||
defer fieldDecoderMutex.Unlock()
|
||||
s, ok = fieldDecoderMap[typ]
|
||||
if ok { // the work is already done
|
||||
return s
|
||||
}
|
||||
|
||||
// a struct should have its fields parsed by cachedFieldIdMap already,
|
||||
// so this shouldn't be too sloppy to just pull it
|
||||
m := fieldIdMap[typ]
|
||||
|
||||
// create a map with pre-nil'ed functions for typ
|
||||
s = make([]decoderFunc, typ.NumField())
|
||||
// look over the fields that could be decoded into
|
||||
for _, i := range m {
|
||||
f := typ.Field(i)
|
||||
k := f.Type.Kind()
|
||||
for k == reflect.Ptr {
|
||||
k = f.Type.Elem().Kind()
|
||||
}
|
||||
switch k {
|
||||
case reflect.Int, reflect.Int8, reflect.Int32, reflect.Int64:
|
||||
s[i] = decodeInt
|
||||
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
|
||||
s[i] = decodeUinta
|
||||
case reflect.Slice:
|
||||
s[i] = decodeSlice
|
||||
case reflect.String:
|
||||
s[i] = decodeString
|
||||
case reflect.Struct:
|
||||
s[i] = decodeStruct
|
||||
default:
|
||||
decError(fmt.Sprintf("cannot decode to %s.%s, %s decoding is unsupported ",
|
||||
typ, f.Name, f.Type.Kind()))
|
||||
}
|
||||
}
|
||||
fieldDecoderMap[typ] = s
|
||||
return s
|
||||
}
|
||||
|
||||
*/
|
|
@ -0,0 +1,339 @@
|
|||
// Copyright © 2013 Emery Hemingway
|
||||
// Released under the terms of the GNU Public License version 3
|
||||
|
||||
package ebml
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"encoding/binary"
|
||||
"fmt"
|
||||
"io"
|
||||
"reflect"
|
||||
"time"
|
||||
)
|
||||
|
||||
// readIdFrom reads an Id from a Reader and returns the number of bytes read and the Id
|
||||
func (d *Decoder) readId() (int, Id) {
|
||||
n, err := d.r.Read(d.buf[:1])
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
|
||||
id := Id(d.buf[0])
|
||||
var buf []byte
|
||||
switch {
|
||||
case id >= 0x80:
|
||||
return n, id
|
||||
case id >= 0x40:
|
||||
buf = d.buf[:1]
|
||||
case id >= 0x20:
|
||||
buf = d.buf[:2]
|
||||
case id >= 0x10:
|
||||
buf = d.buf[:3]
|
||||
default:
|
||||
p, err := d.r.Seek(-1, 1)
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
d.r.Read(buf)
|
||||
decError(fmt.Sprintf("invalid Id at reader position 0x%x or EBMLMaxIDLength > 4, next 8 bytes 0x%0.2x", p, buf))
|
||||
}
|
||||
var nn int
|
||||
nn, err = d.r.Read(buf)
|
||||
n += nn
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
for _, c := range buf {
|
||||
id <<= 8
|
||||
id += Id(c)
|
||||
}
|
||||
return n, id
|
||||
}
|
||||
|
||||
// readSizeFrom reads a size from a Reader and returns the number of bytes read and the size
|
||||
func (d *Decoder) readSize() (int, int64) {
|
||||
n, err := d.r.Read(d.buf[:1])
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
size := int64(d.buf[0])
|
||||
var buf []byte
|
||||
switch {
|
||||
case size >= 0x80:
|
||||
size -= 0x80
|
||||
return n, size
|
||||
case size >= 0x40:
|
||||
size -= 0x40
|
||||
buf = d.buf[:1]
|
||||
case size >= 0x20:
|
||||
size -= 0x20
|
||||
buf = d.buf[:2]
|
||||
case size >= 0x10:
|
||||
size -= 0x10
|
||||
buf = d.buf[:3]
|
||||
case size >= 0x08:
|
||||
size -= 0x08
|
||||
buf = d.buf[:4]
|
||||
case size >= 0x04:
|
||||
size -= 0x04
|
||||
buf = d.buf[:5]
|
||||
case size >= 0x02:
|
||||
size -= 0x02
|
||||
buf = d.buf[:6]
|
||||
case size >= 0x01:
|
||||
size -= 0x01
|
||||
buf = d.buf[:7]
|
||||
}
|
||||
var nn int
|
||||
nn, err = d.r.Read(buf)
|
||||
n += nn
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
for _, c := range buf {
|
||||
size <<= 8
|
||||
size += int64(c)
|
||||
}
|
||||
return n, size
|
||||
}
|
||||
|
||||
type decoderFunc func(d *Decoder, id Id, size int64, v reflect.Value)
|
||||
|
||||
/* Sadly this using this table results in 'initialization loops' during building
|
||||
var decoderFuncTable = [...]decoderFunc{
|
||||
reflect.Uint: decodeUint,
|
||||
reflect.Uint8: decodeUint,
|
||||
reflect.Uint16: decodeUint,
|
||||
reflect.Uint32: decodeUint,
|
||||
reflect.Uint64: decodeUint,
|
||||
reflect.Float32: decodeFloat,
|
||||
reflect.Float64: decodeFloat,
|
||||
reflect.Slice: decodeSlice,
|
||||
reflect.String: decodeString,
|
||||
reflect.Struct: decodeStruct,
|
||||
}
|
||||
*/
|
||||
|
||||
func decodeValue(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
if um, ok := v.Interface().(Unmarshaler); ok {
|
||||
if v.Kind() == reflect.Ptr && v.IsNil() {
|
||||
v.Set(reflect.New(v.Type().Elem()))
|
||||
um = v.Interface().(Unmarshaler)
|
||||
}
|
||||
|
||||
rf := um.UnmarshalEBML(size)
|
||||
r := io.LimitReader(d.r, size)
|
||||
rf.ReadFrom(r)
|
||||
return
|
||||
}
|
||||
|
||||
// If we got an interface or a pointer, dereference it.
|
||||
for v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface {
|
||||
if v.IsNil() {
|
||||
v.Set(reflect.New(v.Type().Elem()))
|
||||
}
|
||||
v = v.Elem()
|
||||
}
|
||||
|
||||
// look up the function to decode to value v
|
||||
var fn decoderFunc
|
||||
// I wanted to use an array of functions indexed by reflect.Kind,
|
||||
// but kept getting initialization loop build errors
|
||||
switch v.Kind() {
|
||||
case reflect.Int, reflect.Int8, reflect.Int32, reflect.Int64:
|
||||
fn = decodeInt
|
||||
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
|
||||
fn = decodeUint
|
||||
case reflect.Float32:
|
||||
fn = decodeFloat32
|
||||
case reflect.Float64:
|
||||
fn = decodeFloat64
|
||||
case reflect.Slice:
|
||||
fn = decodeSlice
|
||||
case reflect.String:
|
||||
fn = decodeString
|
||||
case reflect.Struct:
|
||||
if _, ok := v.Interface().(time.Time); ok {
|
||||
fn = decodeTime
|
||||
} else {
|
||||
fn = decodeStruct
|
||||
}
|
||||
default:
|
||||
decError(fmt.Sprintf("unsupported type %v", v.Type()))
|
||||
}
|
||||
fn(d, id, size, v)
|
||||
}
|
||||
|
||||
func decodeInt(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
_, err := d.r.Read(d.buf[:size])
|
||||
x := int64(int8(d.buf[0]))
|
||||
for _, c := range d.buf[1:size] {
|
||||
x <<= 8
|
||||
x += int64(c)
|
||||
}
|
||||
if x == 0 {
|
||||
return
|
||||
}
|
||||
if v.OverflowInt(x) {
|
||||
decError(fmt.Sprintf("element %s value %d overflows %s", id, x, v.Type()))
|
||||
}
|
||||
v.SetInt(x)
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
}
|
||||
|
||||
func decodeUint(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
_, err := d.r.Read(d.buf[:size])
|
||||
x := uint64(d.buf[0])
|
||||
for _, c := range d.buf[1:size] {
|
||||
x <<= 8
|
||||
x += uint64(c)
|
||||
}
|
||||
if x == 0 {
|
||||
return
|
||||
}
|
||||
if v.OverflowUint(x) {
|
||||
decError(fmt.Sprintf("element %s value %d overflows %s", id, x, v.Type()))
|
||||
}
|
||||
v.SetUint(x)
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
}
|
||||
|
||||
func decodeFloat32(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
var x float32
|
||||
if size != 4 {
|
||||
decError(fmt.Sprintf("cannot decode a float of len %d to a float32", size))
|
||||
}
|
||||
|
||||
buf := d.buf[:size]
|
||||
_, err := d.r.Read(buf)
|
||||
if err != nil && err != io.EOF {
|
||||
decError(err.Error())
|
||||
}
|
||||
err = binary.Read(bytes.NewReader(buf), binary.BigEndian, &x)
|
||||
if err != nil {
|
||||
println(fmt.Sprintf("%x", buf))
|
||||
decError(err.Error())
|
||||
}
|
||||
v.SetFloat(float64(x))
|
||||
}
|
||||
|
||||
func decodeFloat64(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
var x float64
|
||||
if size != 8 {
|
||||
decError(fmt.Sprintf("cannot decode a float of len %d to a float64", size))
|
||||
}
|
||||
|
||||
buf := d.buf[:size]
|
||||
_, err := d.r.Read(buf)
|
||||
if err != nil && err != io.EOF {
|
||||
decError(err.Error())
|
||||
}
|
||||
err = binary.Read(bytes.NewReader(buf), binary.BigEndian, &x)
|
||||
if err != nil {
|
||||
println(fmt.Sprintf("%x", buf))
|
||||
decError(err.Error())
|
||||
}
|
||||
v.SetFloat(x)
|
||||
}
|
||||
|
||||
func decodeSlice(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
if _, ok := v.Interface().([]byte); ok {
|
||||
var buf []byte
|
||||
if size <= 8 {
|
||||
buf = d.buf[:size]
|
||||
} else {
|
||||
buf = make([]byte, int(size))
|
||||
}
|
||||
_, err := d.r.Read(buf)
|
||||
v.Set(reflect.ValueOf(buf))
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// TODO(Emery): would be nice to use reflect.Append()
|
||||
n := v.Len()
|
||||
if n >= v.Cap() {
|
||||
newcap := v.Cap() + v.Cap()/2
|
||||
if newcap < 4 {
|
||||
newcap = 4
|
||||
}
|
||||
newv := reflect.MakeSlice(v.Type(), n+1, newcap)
|
||||
reflect.Copy(newv, v)
|
||||
v.Set(newv)
|
||||
} else {
|
||||
v.SetLen(n + 1)
|
||||
}
|
||||
decodeValue(d, id, size, v.Index(n))
|
||||
}
|
||||
|
||||
func decodeString(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
buf := make([]byte, size)
|
||||
_, err := d.r.Read(buf)
|
||||
v.SetString(string(buf))
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
}
|
||||
|
||||
func decodeStruct(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
t := v.Type()
|
||||
// get Id to field mappings
|
||||
idField := cachedFieldIdMap(t)
|
||||
// BUG(Emery): not caching decoder funtions for struct fields is suboptimal
|
||||
//fieldFunc := cachedFieldDecoderTable(t)
|
||||
|
||||
var n int
|
||||
var subId Id
|
||||
var subSize int64
|
||||
var ok bool
|
||||
for size > 0 {
|
||||
// read and and size
|
||||
n, subId = d.readId()
|
||||
size -= int64(n)
|
||||
n, subSize = d.readSize()
|
||||
size -= int64(n)
|
||||
|
||||
// look up if the subId should decode into a field
|
||||
if n, ok = idField[subId]; ok {
|
||||
decodeValue(d, subId, subSize, v.Field(n))
|
||||
/*
|
||||
subV = v.Field(n)
|
||||
// Derefence pointer
|
||||
for subV.Kind() == reflect.Ptr {
|
||||
subV = subV.Elem()
|
||||
}
|
||||
|
||||
// use the cached decoder funtion for field
|
||||
fieldFunc[n]
|
||||
*/
|
||||
} else {
|
||||
d.r.Seek(size, 0)
|
||||
}
|
||||
size -= subSize
|
||||
}
|
||||
}
|
||||
|
||||
func decodeTime(d *Decoder, id Id, size int64, v reflect.Value) {
|
||||
if size != 8 {
|
||||
decError(fmt.Sprintf("%d is an invalid length for a date value", size))
|
||||
}
|
||||
_, err := d.r.Read(d.buf)
|
||||
|
||||
date := time.Duration(int8(d.buf[0]))
|
||||
for _, c := range d.buf[1:] {
|
||||
date <<= 8
|
||||
date += time.Duration(c)
|
||||
}
|
||||
v.Set(reflect.ValueOf(epoch.Add(date))) // epoch defined in ebml.go
|
||||
|
||||
if err != nil {
|
||||
decError(err.Error())
|
||||
}
|
||||
}
|
|
@ -0,0 +1,128 @@
|
|||
// Copyright © 2013 Emery Hemingway
|
||||
// Released under the terms of the GNU Public License version 3
|
||||
|
||||
/*
|
||||
Package ebml marshals and unmarshals Go structs to and from
|
||||
the Exensible Binary Markup Langauge.
|
||||
*/
|
||||
package ebml
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"fmt"
|
||||
"reflect"
|
||||
"strconv"
|
||||
"time"
|
||||
)
|
||||
|
||||
// Header is a struct for encoding and decoding EBML streams.
|
||||
//
|
||||
// The following could be a valid top-level struct for
|
||||
// representing Matroska streams:
|
||||
// type Matroska struct {
|
||||
// ebml.Header
|
||||
// Segment []Segment `ebml:"18538067"`
|
||||
// }
|
||||
//
|
||||
// You will however need to populate field values in Header
|
||||
// to form a valid EBML document.
|
||||
type Header struct {
|
||||
// BUG(Emery): Setting default and fallback values in
|
||||
// struct field tags is not supported.
|
||||
EbmlId Id `ebml:"1a45dfa3"`
|
||||
EBMLVersion uint8 `ebml:"4286"`
|
||||
EBMLReadVersion uint8 `ebml:"42f7"`
|
||||
EBMLMaxIDLength uint8 `ebml:"42f2"`
|
||||
EBMLMaxSizeLength uint8 `ebml:"42f3"`
|
||||
DocType string `ebml:"4282"`
|
||||
DocTypeVersion uint8 `ebml:"4287"`
|
||||
DocTypeReadVersion uint8 `ebml:"4285"`
|
||||
}
|
||||
|
||||
// Id is a type that identifies an ebml element.
|
||||
type Id uint64
|
||||
|
||||
func (id Id) len() (l int64) {
|
||||
switch {
|
||||
case id > 0x80 && id < 0xFF:
|
||||
l = 1
|
||||
case id > 0x4000 && id < 0x7FFF:
|
||||
l = 2
|
||||
case id > 0x200000 && id < 0x3FFFFF:
|
||||
l = 3
|
||||
case id > 0x10000000 && id < 0x3FFFFFFF:
|
||||
l = 4
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// Bytes returns an Id in byte slice form
|
||||
func (id Id) bytes() []byte {
|
||||
var l int
|
||||
switch {
|
||||
case id > 0x80 && id < 0xFF:
|
||||
l = 1
|
||||
|
||||
case id > 0x4000 && id < 0x7FFF:
|
||||
l = 2
|
||||
|
||||
case id > 0x200000 && id < 0x3FFFFF:
|
||||
l = 3
|
||||
|
||||
case id > 0x10000000 && id < 0x3FFFFFFF:
|
||||
l = 4
|
||||
|
||||
default:
|
||||
panic(fmt.Errorf("invalid element ID %s", id))
|
||||
}
|
||||
b := make([]byte, l)
|
||||
for l > 1 {
|
||||
l--
|
||||
b[l] = byte(id)
|
||||
id >>= 8
|
||||
}
|
||||
b[0] = byte(id)
|
||||
return b
|
||||
}
|
||||
|
||||
// NewIdFromString is a convience fuction that returns an Id
|
||||
// for a string of hexadecimal.
|
||||
func NewIdFromString(s string) (Id, error) {
|
||||
x, err := strconv.ParseUint(s, 16, 64)
|
||||
if err != nil {
|
||||
return 0, err
|
||||
}
|
||||
return Id(x), nil
|
||||
}
|
||||
|
||||
// String implements the Stringer interface, returning Id in
|
||||
// hexadecimal form.
|
||||
func (id Id) String() string {
|
||||
return strconv.FormatUint(uint64(id), 16)
|
||||
}
|
||||
|
||||
// getId parses a struct for "EbmlId"
|
||||
func getId(v reflect.Value) (id Id) {
|
||||
v = reflect.Indirect(v)
|
||||
t := v.Type()
|
||||
if f, ok := t.FieldByName("EbmlId"); ok {
|
||||
id = v.FieldByIndex(f.Index).Interface().(Id)
|
||||
if id == 0 {
|
||||
var err error
|
||||
id, err = NewIdFromString(f.Tag.Get("ebml"))
|
||||
if err != nil {
|
||||
panic(errors.New("cannot resolve EBML Id for " + t.Name() + ", " + err.Error()))
|
||||
}
|
||||
}
|
||||
} else {
|
||||
if n := t.Name(); n == "" {
|
||||
panic(errors.New("cannot resolve EBML Id for anonymous struct"))
|
||||
} else {
|
||||
panic(errors.New("cannot resolve EBML Id for " + n))
|
||||
}
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// EBML epoch is the beginning of this millennium
|
||||
var epoch = time.Date(2001, time.January, 1, 0, 0, 0, 0, time.UTC)
|
|
@ -0,0 +1,370 @@
|
|||
// Copyright © 2013 Emery Hemingway
|
||||
// Released under the terms of the GNU Public License version 3
|
||||
|
||||
package ebml
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"io"
|
||||
"io/ioutil"
|
||||
"math/rand"
|
||||
"reflect"
|
||||
"testing"
|
||||
"time"
|
||||
)
|
||||
|
||||
func init() {
|
||||
rand.Seed(time.Now().UnixNano())
|
||||
}
|
||||
|
||||
/*
|
||||
func ExampleHeader() {
|
||||
var headerA, headerB Header
|
||||
headerA.EBMLVersion = 1
|
||||
headerA.EBMLReadVersion = 1
|
||||
headerA.EBMLMaxIDLength = 1
|
||||
headerA.EBMLMaxSizeLength = 1
|
||||
headerA.DocType = "matroska"
|
||||
headerA.DocTypeVersion = 1
|
||||
headerA.DocTypeReadVersion = 1
|
||||
|
||||
b, _ := Marshal(headerA)
|
||||
|
||||
src := bytes.NewReader(b)
|
||||
dec := NewDecoder(src)
|
||||
|
||||
dec.Decode(&headerB)
|
||||
|
||||
fmt.Printf("0x%x DeepEqual: %v", b, reflect.DeepEqual(headerA, headerB))
|
||||
// Output:
|
||||
// 0x1a45dfa3a34286810142f7810142f2810142f381014282886d6174726f736b614287810142858101 DeepEqual: true
|
||||
}
|
||||
|
||||
func ExampleMarshal() {
|
||||
DoDad := new(struct {
|
||||
EbmlId Id `ebml:"3f0000"`
|
||||
DoHickey uint `ebml:"4242"`
|
||||
ThingaMabob string `ebml:"4243"`
|
||||
HumDinger int `ebml:"4244"`
|
||||
})
|
||||
|
||||
DoDad.DoHickey = 70000
|
||||
DoDad.ThingaMabob = "huzah"
|
||||
DoDad.HumDinger = -92387
|
||||
|
||||
b, err := Marshal(*DoDad)
|
||||
if err != nil {
|
||||
fmt.Println(err)
|
||||
}
|
||||
fmt.Printf("0x%x\n", b)
|
||||
|
||||
// Output:
|
||||
// 0x3f00009442428301117042438568757a6168424483fe971d
|
||||
}
|
||||
|
||||
func ExampleUnmarshal() {
|
||||
data := []byte{
|
||||
0x3f, 0x00, 0x00, 0x94,
|
||||
0x42, 0x42, 0x83, 0x01, 0x11, 0x70,
|
||||
0x42, 0x43, 0x85, 0x68, 0x75, 0x7a, 0x61, 0x68,
|
||||
0x42, 0x44, 0x83, 0xfe, 0x97, 0x1d,
|
||||
}
|
||||
|
||||
DoDad := new(struct {
|
||||
EbmlId Id `ebml:"3f0000"`
|
||||
DoHickey uint `ebml:"4242"`
|
||||
ThingaMabob string `ebml:"4243"`
|
||||
HumDinger int `ebml:"4244"`
|
||||
})
|
||||
|
||||
err := Unmarshal(data, DoDad)
|
||||
if err != nil {
|
||||
fmt.Println(err)
|
||||
}
|
||||
fmt.Printf("%v\n", DoDad)
|
||||
// Output:
|
||||
// &{0 70000 huzah -92387}
|
||||
}
|
||||
*/
|
||||
|
||||
type intTestStruct struct {
|
||||
EbmlId Id `ebml:"81"`
|
||||
I int `ebml:"88"`
|
||||
}
|
||||
|
||||
func TestInt(t *testing.T) {
|
||||
var in, out intTestStruct
|
||||
in.I = rand.Int()
|
||||
|
||||
buf, err := Marshal(in)
|
||||
if err != nil {
|
||||
t.Fatalf("marshal int %d: %s\n buf: %x", in.I, err, buf)
|
||||
return
|
||||
}
|
||||
|
||||
err = Unmarshal(buf, &out)
|
||||
if err != nil && err != io.EOF {
|
||||
t.Fatalf("unmarshal int %d: %s\n buf: %x", in.I, err, buf)
|
||||
return
|
||||
}
|
||||
if !reflect.DeepEqual(in, out) {
|
||||
t.Fatalf("marshal and unmarshal int: in=%0.2x out=%0.2x", in.I, out.I)
|
||||
return
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
func BenchmarkMarshalInt(b *testing.B) {
|
||||
var (
|
||||
in intTestStruct
|
||||
buf []byte
|
||||
err error
|
||||
)
|
||||
in.I = rand.Int()
|
||||
for i := 0; i < b.N; i++ {
|
||||
_, err = Marshal(in)
|
||||
if err != nil {
|
||||
b.Fatalf("marshal int %d: %s\n buf: %x", in.I, err, buf)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkUnmarshalInt(b *testing.B) {
|
||||
var (
|
||||
in, out intTestStruct
|
||||
buf []byte
|
||||
err error
|
||||
)
|
||||
in.I = rand.Int()
|
||||
buf, err = Marshal(in)
|
||||
if err != nil {
|
||||
b.Fatalf("marshal int %d: %s\n buf: %x", in.I, err, buf)
|
||||
return
|
||||
}
|
||||
for i := 0; i < b.N; i++ {
|
||||
err = Unmarshal(buf, &out)
|
||||
if err != nil && err != io.EOF {
|
||||
b.Fatalf("unmarshal int %d: %s\n buf: %x", in.I, err, buf)
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
type uintTestStruct struct {
|
||||
EbmlId Id `ebml:"81"`
|
||||
I uint `ebml:"88"`
|
||||
}
|
||||
|
||||
func TestUint(t *testing.T) {
|
||||
var in, out uintTestStruct
|
||||
|
||||
in.I = uint(rand.Int63())
|
||||
buf, err := Marshal(in)
|
||||
if err != nil {
|
||||
t.Fatalf("marshal uint %d: %s\n buf: %x", in.I, err, buf)
|
||||
}
|
||||
|
||||
err = Unmarshal(buf, &out)
|
||||
if err != nil && err != io.EOF {
|
||||
t.Fatalf("unmarshal uint %d: %s\n buf: %x", in.I, err, buf)
|
||||
}
|
||||
|
||||
if !reflect.DeepEqual(in, out) {
|
||||
t.Fatalf("marshal and unmarshal uint: in=%0.2x out=%0.2x", in.I, out.I)
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkMarshalUint(b *testing.B) {
|
||||
var (
|
||||
in uintTestStruct
|
||||
err error
|
||||
)
|
||||
|
||||
in.I = uint(rand.Int63())
|
||||
for i := 0; i < b.N; i++ {
|
||||
if _, err = Marshal(in); err != nil {
|
||||
b.Fatalf("marshal uint %d: %s\n buf: %x", in.I, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkUnmarshalUint(b *testing.B) {
|
||||
var (
|
||||
in, out uintTestStruct
|
||||
buf []byte
|
||||
err error
|
||||
)
|
||||
|
||||
in.I = uint(rand.Int63())
|
||||
buf, err = Marshal(in)
|
||||
if err != nil {
|
||||
b.Fatalf("marshal uint %d: %s\n buf: %x", in.I, err, buf)
|
||||
}
|
||||
for i := 0; i < b.N; i++ {
|
||||
if err = Unmarshal(buf, &out); err != nil && err != io.EOF {
|
||||
b.Fatalf("unmarshal uint %d: %s\n buf: %x", in.I, err, buf)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
type floatTestStruct struct {
|
||||
EbmlId Id `ebml:"81"`
|
||||
F float32 `ebml:"88"`
|
||||
FF float64 `ebml:"89"`
|
||||
}
|
||||
|
||||
func TestFloat(t *testing.T) {
|
||||
var in, out floatTestStruct
|
||||
|
||||
in.F, in.FF = rand.Float32(), rand.Float64()
|
||||
buf, err := Marshal(in)
|
||||
if err != nil {
|
||||
t.Fatalf("encode floats %f %f: %s\nbuf: %x", in.F, in.FF, err, buf)
|
||||
return
|
||||
}
|
||||
if err = Unmarshal(buf, &out); err != nil {
|
||||
t.Fatalf("decode floats %f %f: %s\nbuf: %x", in.FF, in.FF, err, buf)
|
||||
return
|
||||
}
|
||||
if !reflect.DeepEqual(in, out) {
|
||||
t.Errorf("encode/decode float mismatch: in=%f,%f out=%f,%f\n%x", in.F, in.FF, out.F, out.FF, buf)
|
||||
return
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkMarshalFloat(b *testing.B) {
|
||||
var (
|
||||
in floatTestStruct
|
||||
err error
|
||||
)
|
||||
in.F, in.FF = rand.Float32(), rand.Float64()
|
||||
|
||||
for i := 0; i < b.N; i++ {
|
||||
if _, err = Marshal(in); err != nil {
|
||||
b.Fatalf("encode floats %f %f: %s\nbuf: %x", in.F, in.FF, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkUnmarshalFloat(b *testing.B) {
|
||||
var (
|
||||
in, out floatTestStruct
|
||||
buf []byte
|
||||
err error
|
||||
)
|
||||
in.F, in.FF = rand.Float32(), rand.Float64()
|
||||
if buf, err = Marshal(in); err != nil {
|
||||
b.Fatalf("encode floats %f %f: %s\nbuf: %x", in.F, in.FF, err, buf)
|
||||
return
|
||||
}
|
||||
for i := 0; i < b.N; i++ {
|
||||
if err = Unmarshal(buf, &out); err != nil {
|
||||
b.Fatalf("decode floats %f %f: %s", in.F, in.FF, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
type dateTestStruct struct {
|
||||
EbmlId Id `ebml:"81"`
|
||||
D time.Time `ebml:"82"`
|
||||
}
|
||||
|
||||
func TestDate(t *testing.T) {
|
||||
now := time.Now()
|
||||
I := rand.Int63n(1 << 62)
|
||||
|
||||
var in, out dateTestStruct
|
||||
|
||||
for i := 0; i < 32; i++ {
|
||||
date := now.Add(time.Duration(I))
|
||||
|
||||
in.D = date
|
||||
buf, err := Marshal(in)
|
||||
if err != nil {
|
||||
t.Fatalf("marshal time.Time %v: %s\n buf: %x", date, err, buf)
|
||||
}
|
||||
|
||||
err = Unmarshal(buf, &out)
|
||||
if err != nil && err != io.EOF {
|
||||
t.Fatalf("unmarshal time.Time %v: %s\n buf: %x", date, err, buf)
|
||||
}
|
||||
|
||||
if !in.D.Equal(out.D) {
|
||||
t.Fatalf("marshal and unmarshal time.Time: in=%v out=%v", in.D, out.D)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
type stringTest struct {
|
||||
EbmlId Id `ebml:"81"`
|
||||
S string `ebml:"82"`
|
||||
}
|
||||
|
||||
func TestString(t *testing.T) {
|
||||
var in, out stringTest
|
||||
in.S = "wrong me not good sister, nor wrong yourself"
|
||||
buf, err := Marshal(in)
|
||||
if err != nil {
|
||||
t.Fatal("marshal string failed:", err)
|
||||
}
|
||||
if err = Unmarshal(buf, &out); err != nil {
|
||||
t.Fatalf("unmarshal string failed: %s\n %x", err, buf)
|
||||
}
|
||||
|
||||
if in.S != out.S {
|
||||
t.Fatalf("%s != %s\n%x", in.S, out.S, buf)
|
||||
}
|
||||
}
|
||||
|
||||
type benchTestStruct struct {
|
||||
EbmlId Id `ebml:"81"`
|
||||
A uint `ebml:"4011"`
|
||||
B int64 `ebml:"200011"`
|
||||
C float64 `ebml:"10000011"`
|
||||
D string `ebml:"3FFFFFFE"`
|
||||
}
|
||||
|
||||
func BenchmarkEncoding(b *testing.B) {
|
||||
var test benchTestStruct
|
||||
test.A = uint(rand.Int63())
|
||||
test.B = rand.Int63()
|
||||
test.C = rand.Float64()
|
||||
test.D = "of ships and sails and whether pigs have wings"
|
||||
|
||||
var err error
|
||||
b.ResetTimer()
|
||||
enc := NewEncoder(ioutil.Discard)
|
||||
for i := 0; i < b.N; i++ {
|
||||
err = enc.Encode(test)
|
||||
if err != nil {
|
||||
b.Fatal(err.Error())
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkDecoding(b *testing.B) {
|
||||
control := new(benchTestStruct)
|
||||
|
||||
control.A = uint(rand.Int63())
|
||||
control.B = rand.Int63()
|
||||
control.C = rand.Float64()
|
||||
control.D = "of ships and sails and whether pigs have wings"
|
||||
|
||||
buf, err := Marshal(control)
|
||||
r := bytes.NewReader(buf)
|
||||
b.ResetTimer()
|
||||
|
||||
dec := NewDecoder(r)
|
||||
for i := 0; i < b.N; i++ {
|
||||
var test benchTestStruct
|
||||
err = dec.Decode(&test)
|
||||
if err != nil {
|
||||
b.Fatal(err.Error())
|
||||
}
|
||||
|
||||
if !reflect.DeepEqual(control, test) {
|
||||
b.Fatalf("not equal\n%v\n%v", control, test)
|
||||
}
|
||||
r.Seek(0, 0)
|
||||
}
|
||||
}
|
|
@ -0,0 +1,421 @@
|
|||
// Copyright © 2013 Emery Hemingway
|
||||
// Released under the terms of the GNU Public License version 3
|
||||
|
||||
package ebml
|
||||
|
||||
import (
|
||||
"encoding/binary"
|
||||
"fmt"
|
||||
"io"
|
||||
"reflect"
|
||||
"time"
|
||||
)
|
||||
|
||||
var indent string
|
||||
|
||||
type encoder interface {
|
||||
io.WriterTo
|
||||
Size() int64
|
||||
}
|
||||
|
||||
type containerElement struct {
|
||||
// These []bytes can probably be merged
|
||||
id Id
|
||||
size int64
|
||||
header []byte
|
||||
elements []encoder
|
||||
}
|
||||
|
||||
func (ce *containerElement) Append(e encoder) {
|
||||
ce.elements = append(ce.elements, e)
|
||||
ce.size += e.Size()
|
||||
}
|
||||
|
||||
func (ce *containerElement) Size() (n int64) {
|
||||
ce.header = append(ce.id.bytes(), marshalSize(ce.size)...)
|
||||
return int64(len(ce.header)) + ce.size
|
||||
}
|
||||
|
||||
func (ce *containerElement) WriteTo(w io.Writer) (n int64, err error) {
|
||||
if len(ce.header) == 0 {
|
||||
ce.Size() // top level elements don't get Size called
|
||||
}
|
||||
var N int
|
||||
var nn int64
|
||||
N, err = w.Write(ce.header)
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
n += int64(N)
|
||||
|
||||
for _, e := range ce.elements {
|
||||
nn, err = e.WriteTo(w)
|
||||
n += nn
|
||||
if err != nil {
|
||||
break
|
||||
}
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
type simpleElement []byte
|
||||
|
||||
func (b simpleElement) Size() int64 { return int64(len(b)) }
|
||||
func (b simpleElement) WriteTo(w io.Writer) (int64, error) {
|
||||
n, err := w.Write(b)
|
||||
return int64(n), err
|
||||
}
|
||||
|
||||
// sliceElement is a encoder for holding groups of elements, such as a group
|
||||
// elements of the same type that occur more than once in a container.
|
||||
type sliceElement []encoder
|
||||
|
||||
func (se sliceElement) Size() (n int64) {
|
||||
for _, e := range se {
|
||||
n += e.Size()
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
func (se sliceElement) WriteTo(w io.Writer) (n int64, err error) {
|
||||
var nn int64
|
||||
for _, e := range se {
|
||||
nn, err = e.WriteTo(w)
|
||||
n += nn
|
||||
if err != nil {
|
||||
break
|
||||
}
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
type marshalerElement struct {
|
||||
id Id
|
||||
size int64
|
||||
header []byte
|
||||
wt io.WriterTo
|
||||
}
|
||||
|
||||
func (me *marshalerElement) Size() int64 { return me.size }
|
||||
|
||||
func (me *marshalerElement) WriteTo(w io.Writer) (n int64, err error) {
|
||||
var N int
|
||||
var nn int64
|
||||
N, err = w.Write(me.header)
|
||||
n = int64(N)
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
nn, err = me.wt.WriteTo(w)
|
||||
n += nn
|
||||
return
|
||||
}
|
||||
|
||||
func unsupportedTypeError(typ reflect.Type) {
|
||||
encError("unsupported type: " + typ.String())
|
||||
}
|
||||
|
||||
func isEmptyValue(v reflect.Value) bool {
|
||||
switch v.Kind() {
|
||||
case reflect.Array, reflect.Slice, reflect.String:
|
||||
return v.Len() == 0
|
||||
case reflect.Interface, reflect.Ptr:
|
||||
return v.IsNil()
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
func encode(id Id, v reflect.Value) encoder {
|
||||
if m, ok := v.Interface().(Marshaler); ok {
|
||||
size, wt := m.MarshalEBML()
|
||||
header := append(id.bytes(), marshalSize(size)...)
|
||||
return &marshalerElement{id, size, header, wt}
|
||||
}
|
||||
|
||||
if t, ok := v.Interface().(time.Time); ok {
|
||||
return encodeTime(id, t)
|
||||
}
|
||||
|
||||
for v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface {
|
||||
v = v.Elem()
|
||||
}
|
||||
|
||||
switch v.Kind() {
|
||||
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
||||
x := v.Int()
|
||||
return marshalInt(id, x)
|
||||
|
||||
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
|
||||
x := v.Uint()
|
||||
return marshalUint(id, x)
|
||||
|
||||
case reflect.Float32:
|
||||
return float32Element{id, v.Interface().(float32)}
|
||||
|
||||
case reflect.Float64:
|
||||
return float64Element{id, v.Interface().(float64)}
|
||||
|
||||
case reflect.String:
|
||||
return encodeString(id, v)
|
||||
|
||||
case reflect.Slice:
|
||||
return encodeSlice(id, v)
|
||||
|
||||
case reflect.Struct:
|
||||
return encodeStruct(id, v)
|
||||
}
|
||||
unsupportedTypeError(v.Type())
|
||||
return nil
|
||||
}
|
||||
|
||||
const (
|
||||
o1 = 1<<7 - 2
|
||||
o2 = 1<<14 - 2
|
||||
o3 = 1<<21 - 2
|
||||
o4 = 1<<28 - 2
|
||||
o5 = 1<<35 - 2
|
||||
o6 = 1<<42 - 2
|
||||
o7 = 1<<49 - 2
|
||||
o8 = 1<<56 - 2
|
||||
)
|
||||
|
||||
// MarshalSize returns the EBML variable width representation
|
||||
// of an element's size
|
||||
func marshalSize(x int64) []byte {
|
||||
var s int
|
||||
var m byte
|
||||
|
||||
switch {
|
||||
case x == 0:
|
||||
return []byte{byte(0x80)}
|
||||
case x < o1:
|
||||
return []byte{byte(0x80) | byte(x)}
|
||||
case x < o2:
|
||||
s = 2
|
||||
m = 0x40
|
||||
case x < o3:
|
||||
s = 3
|
||||
m = 0x20
|
||||
case x < o4:
|
||||
s = 4
|
||||
m = 0x10
|
||||
case x < o5:
|
||||
s = 5
|
||||
m = 0x08
|
||||
case x < o6:
|
||||
s = 6
|
||||
m = 0x04
|
||||
case x < o7:
|
||||
s = 7
|
||||
m = 0x02
|
||||
case x < o8:
|
||||
s = 8
|
||||
m = 0x01
|
||||
default:
|
||||
encError(fmt.Sprintf("element size %d overflows", x))
|
||||
}
|
||||
b := make([]byte, s)
|
||||
s--
|
||||
for s > 0 {
|
||||
b[s] = byte(x)
|
||||
x >>= 8
|
||||
s--
|
||||
}
|
||||
b[0] = byte(x) | m
|
||||
return b
|
||||
}
|
||||
|
||||
func marshalInt(id Id, x int64) encoder {
|
||||
var xl int
|
||||
if x > 0 {
|
||||
switch {
|
||||
case x < 0x80:
|
||||
xl = 1
|
||||
case x < 0x8000:
|
||||
xl = 2
|
||||
case x < 0x800000:
|
||||
xl = 3
|
||||
case x < 0x80000000:
|
||||
xl = 4
|
||||
case x < 0x8000000000:
|
||||
xl = 5
|
||||
case x < 0x800000000000:
|
||||
xl = 6
|
||||
case x < 0x80000000000000:
|
||||
xl = 7
|
||||
default:
|
||||
xl = 8
|
||||
}
|
||||
} else {
|
||||
switch {
|
||||
case x > -0x7F:
|
||||
xl = 1
|
||||
case x > -0x7FFF:
|
||||
xl = 2
|
||||
case x > -0x7FFFFF:
|
||||
xl = 3
|
||||
case x > -0x7FFFFFFF:
|
||||
xl = 4
|
||||
case x > -0x7FFFFFFFFF:
|
||||
xl = 5
|
||||
case x > -0x7FFFFFFFFFFF:
|
||||
xl = 6
|
||||
case x > -0x7FFFFFFFFFFFFF:
|
||||
xl = 7
|
||||
default:
|
||||
xl = 8
|
||||
}
|
||||
}
|
||||
|
||||
idBuf := id.bytes()
|
||||
l := len(idBuf) + 1 + xl
|
||||
b := make(simpleElement, l)
|
||||
p := copy(b, idBuf)
|
||||
b[p] = 0x80 | byte(xl)
|
||||
p++
|
||||
|
||||
l--
|
||||
b[l] = byte(x)
|
||||
for l > p {
|
||||
l--
|
||||
x >>= 8
|
||||
b[l] = byte(x)
|
||||
}
|
||||
return b
|
||||
}
|
||||
|
||||
func marshalUint(id Id, x uint64) encoder {
|
||||
var xl int
|
||||
switch {
|
||||
case x < 0xFF:
|
||||
xl = 1
|
||||
case x < 0xFFFF:
|
||||
xl = 2
|
||||
case x < 0xFFFFFF:
|
||||
xl = 3
|
||||
case x < 0xFFFFFFFF:
|
||||
xl = 4
|
||||
case x < 0xFFFFFFFFFF:
|
||||
xl = 5
|
||||
case x < 0xFFFFFFFFFFFF:
|
||||
xl = 6
|
||||
case x < 0xFFFFFFFFFFFFFF:
|
||||
xl = 7
|
||||
default:
|
||||
xl = 8
|
||||
}
|
||||
idBuf := id.bytes()
|
||||
|
||||
l := len(idBuf) + 1 + xl
|
||||
b := make(simpleElement, l)
|
||||
p := copy(b, idBuf)
|
||||
b[p] = 0x80 | byte(xl)
|
||||
p++
|
||||
|
||||
l--
|
||||
b[l] = byte(x)
|
||||
for l > p {
|
||||
l--
|
||||
x >>= 8
|
||||
b[l] = byte(x)
|
||||
}
|
||||
return b
|
||||
}
|
||||
|
||||
type float32Element struct {
|
||||
id Id
|
||||
f float32
|
||||
}
|
||||
|
||||
func (e float32Element) Size() int64 { return e.id.len() + 5 }
|
||||
func (e float32Element) WriteTo(w io.Writer) (int64, error) {
|
||||
n, err := w.Write(e.id.bytes())
|
||||
if err == nil {
|
||||
_, err = w.Write([]byte{0x84})
|
||||
if err == nil {
|
||||
err = binary.Write(w, binary.BigEndian, e.f)
|
||||
n += 5
|
||||
}
|
||||
}
|
||||
return int64(n), err
|
||||
}
|
||||
|
||||
type float64Element struct {
|
||||
id Id
|
||||
f float64
|
||||
}
|
||||
|
||||
func (e float64Element) Size() int64 { return e.id.len() + 9 }
|
||||
func (e float64Element) WriteTo(w io.Writer) (int64, error) {
|
||||
n, err := w.Write(e.id.bytes())
|
||||
if err == nil {
|
||||
_, err = w.Write([]byte{0x88})
|
||||
if err == nil {
|
||||
n++
|
||||
err = binary.Write(w, binary.BigEndian, e.f)
|
||||
} else {
|
||||
n += 8
|
||||
}
|
||||
}
|
||||
return int64(n), err
|
||||
}
|
||||
|
||||
func encodeSlice(id Id, v reflect.Value) encoder {
|
||||
if bs, ok := v.Interface().([]byte); ok {
|
||||
idBuf := id.bytes()
|
||||
sizeBuf := marshalSize(int64(len(bs)))
|
||||
buf := make(simpleElement, len(idBuf)+len(sizeBuf)+len(bs))
|
||||
n := copy(buf, idBuf)
|
||||
n += copy(buf[n:], sizeBuf)
|
||||
copy(buf[n:], bs)
|
||||
return buf
|
||||
}
|
||||
|
||||
l := v.Len()
|
||||
s := make(sliceElement, l)
|
||||
for i := 0; i < l; i++ {
|
||||
s[i] = encode(id, v.Index(i))
|
||||
}
|
||||
return s
|
||||
}
|
||||
|
||||
func encodeString(id Id, v reflect.Value) encoder {
|
||||
sb := []byte(v.String())
|
||||
l := len(sb)
|
||||
sz := marshalSize(int64(l))
|
||||
idBuf := id.bytes()
|
||||
b := make(simpleElement, len(idBuf)+len(sz)+l)
|
||||
n := copy(b, idBuf)
|
||||
n += copy(b[n:], sz)
|
||||
copy(b[n:], sb)
|
||||
return b
|
||||
}
|
||||
|
||||
func encodeStruct(id Id, v reflect.Value) encoder {
|
||||
e := &containerElement{id: id}
|
||||
for fid, i := range cachedFieldIdMap(v.Type()) {
|
||||
fv := v.Field(i)
|
||||
if !fv.IsValid() || isEmptyValue(fv) {
|
||||
continue
|
||||
}
|
||||
fe := encode(fid, fv)
|
||||
if e != nil {
|
||||
e.Append(fe)
|
||||
}
|
||||
}
|
||||
return e
|
||||
}
|
||||
|
||||
func encodeTime(id Id, t time.Time) encoder {
|
||||
d := t.Sub(epoch) // epoch defined in ebml.go
|
||||
|
||||
idb := id.bytes()
|
||||
b := make(simpleElement, len(idb)+9)
|
||||
n := copy(b, idb)
|
||||
b[n] = 0x88 // length will be 8
|
||||
for i := len(b) - 1; i > n; i-- {
|
||||
b[i] = byte(d)
|
||||
d >>= 8
|
||||
}
|
||||
return b
|
||||
}
|
|
@ -0,0 +1,17 @@
|
|||
// Copyright © 2013 Emery Hemingway
|
||||
// Released under the terms of the GNU Public License version 3
|
||||
|
||||
package ebml
|
||||
|
||||
// A ebmlError is used to distinguish errors (panics) generated in this package.
|
||||
type ebmlError string
|
||||
|
||||
func (e ebmlError) Error() string { return string(e) }
|
||||
|
||||
func encError(s string) {
|
||||
panic(ebmlError("ebml encoder: " + s))
|
||||
}
|
||||
|
||||
func decError(s string) {
|
||||
panic(ebmlError("ebml decoder: " + s))
|
||||
}
|
|
@ -0,0 +1,94 @@
|
|||
// Copyright © 2013 Emery Hemingway
|
||||
// Released under the terms of the GNU Public License version 3
|
||||
|
||||
package ebml
|
||||
|
||||
import (
|
||||
"bufio"
|
||||
"io"
|
||||
"os"
|
||||
)
|
||||
|
||||
type fileAbstraction struct {
|
||||
filename string
|
||||
info os.FileInfo
|
||||
}
|
||||
|
||||
// NewFileMarshaler returns a Marshaler that reads from a file
|
||||
// during encoding.
|
||||
func NewFileMarshaler(filename string) (Marshaler, error) {
|
||||
info, err := os.Stat(filename)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &fileAbstraction{filename, info}, nil
|
||||
}
|
||||
|
||||
func (f *fileAbstraction) MarshalEBML() (size int64, wt io.WriterTo) {
|
||||
return f.info.Size(), f
|
||||
}
|
||||
|
||||
func (f *fileAbstraction) WriteTo(w io.Writer) (written int64, err error) {
|
||||
var file *os.File
|
||||
file, err = os.Open(f.filename)
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
defer file.Close()
|
||||
// let bufio handle the details
|
||||
return bufio.NewReader(file).WriteTo(w)
|
||||
}
|
||||
|
||||
// NewFileUnmarshaler returns an Unmarshaler that writes to a file
|
||||
// during decoding.
|
||||
func NewFileUnmarshaler(filename string) (Unmarshaler, error) {
|
||||
info, err := os.Stat(filename)
|
||||
if err == nil {
|
||||
return &fileAbstraction{filename, info}, nil
|
||||
}
|
||||
|
||||
// create the file to check write permission before decoding.
|
||||
if !os.IsNotExist(err) {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
var file *os.File
|
||||
file, err = os.OpenFile(filename, os.O_CREATE|os.O_EXCL, 0666)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer file.Close()
|
||||
|
||||
// try again
|
||||
info, err = os.Stat(filename)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &fileAbstraction{filename, info}, nil
|
||||
}
|
||||
|
||||
func (f *fileAbstraction) UnmarshalEBML(n int64) io.ReaderFrom {
|
||||
if f.info.Size() != n {
|
||||
err := os.Truncate(f.filename, n)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
}
|
||||
return f
|
||||
}
|
||||
|
||||
func (f *fileAbstraction) ReadFrom(r io.Reader) (readed int64, err error) {
|
||||
var file *os.File
|
||||
file, err = os.OpenFile(f.filename, os.O_WRONLY, 0)
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
defer file.Close()
|
||||
// let bufio handle the details
|
||||
return bufio.NewWriter(file).ReadFrom(r)
|
||||
}
|
||||
|
||||
var (
|
||||
_ Marshaler = (*fileAbstraction)(nil)
|
||||
_ Unmarshaler = (*fileAbstraction)(nil)
|
||||
)
|
|
@ -0,0 +1,35 @@
|
|||
// +build file
|
||||
// This test is only run with the "file" build tag,
|
||||
// as it touches the filesystem and needs a test file.
|
||||
|
||||
package ebml
|
||||
|
||||
import "testing"
|
||||
|
||||
func TestFile(t *testing.T) {
|
||||
fm, err := NewFileMarshaler("/tmp/test.in")
|
||||
if err != nil {
|
||||
t.Fatal("NewFileMarshaler:", err)
|
||||
}
|
||||
x := &struct {
|
||||
EbmlId Id `ebml:"81"`
|
||||
F Marshaler `ebml:"82"`
|
||||
}{F: fm}
|
||||
b, err := Marshal(x)
|
||||
if err != nil {
|
||||
t.Fatal("Marshal:", err)
|
||||
}
|
||||
|
||||
fu, err := NewFileUnmarshaler("/tmp/test.out")
|
||||
if err != nil {
|
||||
t.Fatal("NewFileUnmarshaler:", err)
|
||||
}
|
||||
y := &struct {
|
||||
EbmlId Id `ebml:"81"`
|
||||
F Unmarshaler `ebml:"82"`
|
||||
}{F: fu}
|
||||
err = Unmarshal(b, y)
|
||||
if err != nil {
|
||||
t.Fatal("Unmarshal:", err)
|
||||
}
|
||||
}
|
|
@ -0,0 +1,43 @@
|
|||
// idtest is a utility for checking the validity of EBML ids
|
||||
package main
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"github.com/ehmry/encoding/ebml"
|
||||
"os"
|
||||
)
|
||||
|
||||
func main() {
|
||||
for _, s := range os.Args[1:] {
|
||||
id, err := ebml.NewIdFromString(s)
|
||||
if err != nil {
|
||||
fmt.Println(err)
|
||||
continue
|
||||
}
|
||||
|
||||
b := id.Bytes()
|
||||
c := b[0]
|
||||
var good bool
|
||||
switch l := len(b); l {
|
||||
case 1:
|
||||
good = c <= 0xff && c > 0x80
|
||||
case 2:
|
||||
good = c <= 0x7f && c > 0x40
|
||||
case 3:
|
||||
good = c <= 0x3f && c > 0x20
|
||||
case 4:
|
||||
good = c <= 0x1f && c > 0x10
|
||||
}
|
||||
|
||||
if good {
|
||||
fmt.Print("Id is good: ")
|
||||
} else {
|
||||
fmt.Print("Id is bad: ")
|
||||
}
|
||||
fmt.Printf("% 11s ", id)
|
||||
for _, c := range b {
|
||||
fmt.Printf(".%08b", c)
|
||||
}
|
||||
fmt.Println()
|
||||
}
|
||||
}
|
|
@ -0,0 +1,155 @@
|
|||
// Copyright © 2013 Emery Hemingway
|
||||
// Released under the terms of the GNU Public License version 3
|
||||
|
||||
package ebml
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"fmt"
|
||||
"io"
|
||||
"reflect"
|
||||
"runtime"
|
||||
)
|
||||
|
||||
// An Encoder writes EBML data to an output stream.
|
||||
type Encoder struct {
|
||||
w io.Writer
|
||||
err error
|
||||
}
|
||||
|
||||
// NewEncoder returns a new Encoder that writes to w.
|
||||
func NewEncoder(w io.Writer) *Encoder {
|
||||
return &Encoder{w: w}
|
||||
}
|
||||
|
||||
// Encode writes the EBML binary encoding of element to an Encoder stream.
|
||||
func (enc *Encoder) Encode(element interface{}) (err error) {
|
||||
if enc.err != nil {
|
||||
return enc.err
|
||||
}
|
||||
|
||||
// encoding doesn't use error internally, but panics if there is a
|
||||
// problem and then unwinds up to here.
|
||||
defer func() {
|
||||
if r := recover(); r != nil {
|
||||
if _, ok := r.(runtime.Error); ok {
|
||||
panic(r)
|
||||
}
|
||||
err = r.(error)
|
||||
}
|
||||
}()
|
||||
|
||||
v := reflect.ValueOf(element)
|
||||
id := getId(v)
|
||||
|
||||
elem := encode(id, v)
|
||||
if elem != nil {
|
||||
_, err = elem.WriteTo(enc.w)
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// A Decoder decodes EBML data from a ReadSeeker
|
||||
type Decoder struct {
|
||||
r io.ReadSeeker
|
||||
buf []byte // this is a resuable buffer for decoding
|
||||
err error
|
||||
}
|
||||
|
||||
// NewDecoder returns a new decoder that decodes from r.
|
||||
func NewDecoder(r io.ReadSeeker) *Decoder {
|
||||
// TODO(Emery): just ask for a io.Reader and try and make it
|
||||
// an io.ReadSeeker
|
||||
return &Decoder{r: r, buf: make([]byte, 8)}
|
||||
}
|
||||
|
||||
// Decode decodes a EBML stream into v.
|
||||
func (d *Decoder) Decode(element interface{}) (err error) {
|
||||
if d.err != nil {
|
||||
return d.err
|
||||
}
|
||||
|
||||
// decoding doesn't use error internally, but panics if there is a
|
||||
// problem and then unwinds up to here.
|
||||
defer func() {
|
||||
if r := recover(); r != nil {
|
||||
if _, ok := r.(runtime.Error); ok {
|
||||
panic(r)
|
||||
}
|
||||
err = r.(error)
|
||||
}
|
||||
}()
|
||||
|
||||
v := reflect.ValueOf(element)
|
||||
for v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface {
|
||||
v = v.Elem()
|
||||
}
|
||||
|
||||
id := getId(v)
|
||||
if n, curId := d.readId(); id != curId {
|
||||
d.r.Seek(int64(-n), 0)
|
||||
return fmt.Errorf("ebml: read stream positioned at element %s not %s", curId, id)
|
||||
}
|
||||
_, size := d.readSize()
|
||||
|
||||
decodeValue(d, id, size, v)
|
||||
return
|
||||
}
|
||||
|
||||
// Marshal returns an EBML representation of element.
|
||||
//
|
||||
// Marshal first determines the Id of element from the field named 'EbmlId',
|
||||
// then recursively traverses element. Any exported struct field of element
|
||||
// with an `ebml` tag will be including in marshalling, with the exception
|
||||
// of fields tagged with `ebml:"-"`.
|
||||
//
|
||||
// The ebml tag should contain a valid EBML id, see the EBML documention for
|
||||
// what constitutes a valid id.
|
||||
func Marshal(element interface{}) ([]byte, error) {
|
||||
buf := new(bytes.Buffer)
|
||||
encoder := NewEncoder(buf)
|
||||
err := encoder.Encode(element)
|
||||
return buf.Bytes(), err
|
||||
}
|
||||
|
||||
// Unmarshal unmarshals EBML data into element.
|
||||
//
|
||||
// Unmarshal first determines the Id of element from the field named 'EbmlId',
|
||||
// then recursively traverses element. Any exported struct field of element
|
||||
// with an `ebml` tag will be including in unmarshalling, with the exception
|
||||
// of fields tagged with `ebml:"-"`.
|
||||
//
|
||||
// The ebml tag should contain a valid EBML id, see the EBML documention for
|
||||
// what constitutes a valid id.
|
||||
func Unmarshal(data []byte, element interface{}) error {
|
||||
return NewDecoder(bytes.NewReader(data)).Decode(element)
|
||||
}
|
||||
|
||||
// Marshaler is the interface implemented by objects that
|
||||
// can marshal themselves into an EBML stream. The WriterTo
|
||||
// should only Write element data, and not the id and size
|
||||
// header of the element. size is the length of the data that
|
||||
// shall be written and is used to build the element header
|
||||
// and compute the size of the parent element before it is
|
||||
// writen to an EBML stream.
|
||||
type Marshaler interface {
|
||||
// BUG(Emery): an embedded Marshaler will trample on a struct
|
||||
MarshalEBML() (size int64, wt io.WriterTo)
|
||||
}
|
||||
|
||||
// Unmarshaler is the interface implemented by objects that
|
||||
// can unmarshal themselves from an EBML stream. The data
|
||||
// read into ReaderFrom will contain the data for the element
|
||||
// being unmarshaled, and not an id or size header.
|
||||
//
|
||||
// n shall be the size of the element data, and it is not the
|
||||
// resposibility of an Unmarshaler to limit reading to n.
|
||||
//
|
||||
// An Unmarshaler is usually sent to the decoding engine as a nil pointer
|
||||
// in a struct and created when a tagged element is encountered, for this
|
||||
// reason the UnmarshalEBML method should behave as if the Unmarshaler is
|
||||
// at a zero value state.
|
||||
type Unmarshaler interface {
|
||||
// BUG(Emery): an embedded Unmarshaler will trample on a struct
|
||||
UnmarshalEBML(n int64) io.ReaderFrom
|
||||
}
|
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Reference in New Issue