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SPDX is an ISO standard for describing licenses in a computer readable format, which is useful when applying license compliance tools and the like to source code. In addition to ensuring that the Wuffs C distribution is properly annotated to the benefit of projects using Wuffs and SPDX-supporting tools, add it everywhere else where there's a license in this repo for consistency, too.
84 lines
3.4 KiB
C
84 lines
3.4 KiB
C
// Copyright 2019 The Wuffs Authors.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//
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// SPDX-License-Identifier: Apache-2.0 OR MIT
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#include <stdio.h>
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// TODO: this 'rough edge' shouldn't be necessary. See
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// https://github.com/google/wuffs/issues/24
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#define WUFFS_CONFIG__MODULE__BASE
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#define WUFFS_IMPLEMENTATION
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#include "./parse.c"
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uint32_t parse(char* p, size_t n) {
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wuffs_base__status status;
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// This next line of code allocates a wuffs_demo__parser on the stack. Stack
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// allocation in C means uninitialized memory, so we need to call
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// wuffs_demo__parser__initialize afterwards.
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//
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// An alternative, allocating on the heap and initializing in a single
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// function call, is to say:
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//
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// wuffs_demo__parser* parser = wuffs_demo__parser__alloc();
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// if (!parser) {
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// // Out of memory.
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// return 0;
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// }
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// // No need to call wuffs_demo__parser__initialize, but don't forget to
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// // free(parser) before this function returns, taking extra care if this
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// // function has multiple return points. Wuffs has no destructor functions
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// // and Wuffs types never hold or own any resources in the RAII sense.
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// // Just free the memory.
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//
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// For stack allocation, the C compiler needs to know
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// sizeof(wuffs_demo__parser), but that compile-time value isn't guaranteed
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// to be stable across Wuffs versions. Stack allocation is therefore only
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// valid when the C file also #define's WUFFS_IMPLEMENTATION. When linking
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// against a separately built Wuffs library (and the Wuffs types in this
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// compilation are incomplete types), you'll have to use heap allocation.
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wuffs_demo__parser parser;
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// Initialize (and check status). An error here means that bad arguments were
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// passed to wuffs_demo__parser__initialize.
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//
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// There are two other categories of not-OK status values, notes and
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// suspensions, but they won't be encountered in this example.
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status = wuffs_demo__parser__initialize(&parser, sizeof__wuffs_demo__parser(),
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WUFFS_VERSION, 0);
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if (!wuffs_base__status__is_ok(&status)) {
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printf("initialize: %s\n", wuffs_base__status__message(&status));
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return 0;
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}
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// True means that the wuffs_base__io_buffer is closed - we are at the end of
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// the input. False would mean that there might be additional data in the
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// byte stream (that this buffer is not large enough to hold all at once).
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//
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// In general, Wuffs' coroutine and suspension status mechanisms let it parse
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// arbitrarily large data streams using fixed sized buffers, but that won't
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// be encountered in this example.
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wuffs_base__io_buffer iobuf =
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wuffs_base__ptr_u8__reader((uint8_t*)p, n, true);
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// Parse (and check status). An error here means that we had invalid input
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// (i.e. "#not a digit" or "#too large").
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//
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// There are two other categories of not-OK status values, notes and
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// suspensions, but they won't be encountered in this example.
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status = wuffs_demo__parser__parse(&parser, &iobuf);
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if (!wuffs_base__status__is_ok(&status)) {
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printf("parse: %s\n", wuffs_base__status__message(&status));
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return 0;
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}
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return wuffs_demo__parser__value(&parser);
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}
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