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Diffstat (limited to 'src/byte_source.h')
| -rw-r--r-- | src/byte_source.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/src/byte_source.h b/src/byte_source.h new file mode 100644 index 00000000..a0dfa140 --- /dev/null +++ b/src/byte_source.h @@ -0,0 +1,118 @@ +/* + Copyright 2011-2020 David Robillard <http://drobilla.net> + + Permission to use, copy, modify, and/or distribute this software for any + purpose with or without fee is hereby granted, provided that the above + copyright notice and this permission notice appear in all copies. + + THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +#ifndef SERD_BYTE_SOURCE_H +#define SERD_BYTE_SOURCE_H + +#include "serd/serd.h" + +#include <assert.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> + +typedef struct { + const uint8_t* filename; + unsigned line; + unsigned col; +} Cursor; + +typedef struct { + SerdSource read_func; ///< Read function (e.g. fread) + SerdStreamErrorFunc error_func; ///< Error function (e.g. ferror) + void* stream; ///< Stream (e.g. FILE) + size_t page_size; ///< Number of bytes to read at a time + size_t buf_size; ///< Number of bytes in file_buf + Cursor cur; ///< Cursor for error reporting + uint8_t* file_buf; ///< Buffer iff reading pages from a file + const uint8_t* read_buf; ///< Pointer to file_buf or read_byte + size_t read_head; ///< Offset into read_buf + uint8_t read_byte; ///< 1-byte 'buffer' used when not paging + bool from_stream; ///< True iff reading from `stream` + bool prepared; ///< True iff prepared for reading + bool eof; ///< True iff end of file reached +} SerdByteSource; + +SerdStatus +serd_byte_source_open_file(SerdByteSource* source, + FILE* file, + bool bulk); + +SerdStatus +serd_byte_source_open_string(SerdByteSource* source, const uint8_t* utf8); + +SerdStatus +serd_byte_source_open_source(SerdByteSource* source, + SerdSource read_func, + SerdStreamErrorFunc error_func, + void* stream, + const uint8_t* name, + size_t page_size); + +SerdStatus +serd_byte_source_close(SerdByteSource* source); + +SerdStatus +serd_byte_source_prepare(SerdByteSource* source); + +SerdStatus +serd_byte_source_page(SerdByteSource* source); + +static inline uint8_t +serd_byte_source_peek(SerdByteSource* source) +{ + assert(source->prepared); + return source->read_buf[source->read_head]; +} + +static inline SerdStatus +serd_byte_source_advance(SerdByteSource* source) +{ + SerdStatus st = SERD_SUCCESS; + + switch (serd_byte_source_peek(source)) { + case '\n': ++source->cur.line; source->cur.col = 0; break; + default: ++source->cur.col; + } + + const bool was_eof = source->eof; + if (source->from_stream) { + source->eof = false; + if (source->page_size > 1) { + if (++source->read_head == source->page_size) { + st = serd_byte_source_page(source); + } else if (source->read_head == source->buf_size) { + source->eof = true; + } + } else { + if (!source->read_func(&source->read_byte, 1, 1, source->stream)) { + source->eof = true; + st = source->error_func(source->stream) ? SERD_ERR_UNKNOWN + : SERD_FAILURE; + } + } + } else if (!source->eof) { + ++source->read_head; // Move to next character in string + if (source->read_buf[source->read_head] == '\0') { + source->eof = true; + } + } + + return (was_eof && source->eof) ? SERD_FAILURE : st; +} + +#endif // SERD_BYTE_SOURCE_H |