69 lines
2.4 KiB
C
69 lines
2.4 KiB
C
#include "stream_buffer.h"
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#include <string.h>
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static foug_bool_t foug_stream_buffer_at_end(void* cookie)
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{
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const foug_buffer_t* buff = (const foug_buffer_t*)cookie;
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return buff->pos >= buff->len;
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}
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static int foug_stream_buffer_error(void* cookie)
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{
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const foug_buffer_t* buff = (const foug_buffer_t*)cookie;
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return buff == NULL || buff->pos > buff->len;
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}
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static size_t foug_stream_buffer_read(void* cookie,
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void* ptr,
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size_t item_size,
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size_t item_count)
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{
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if (item_size > 0 && item_count > 0) {
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foug_buffer_t* buff = (foug_buffer_t*)cookie;
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const size_t buff_remaining_size = buff->len - buff->pos;
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const size_t wanted_read_size = item_size * item_count;
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const size_t next_read_size = wanted_read_size <= buff_remaining_size ? wanted_read_size :
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buff_remaining_size;
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const size_t next_read_item_count = next_read_size / item_size;
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memcpy(ptr, (const char*)buff->ptr + buff->pos, next_read_item_count * item_size);
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buff->pos += next_read_item_count * item_size;
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return next_read_item_count;
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}
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else {
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return 0;
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}
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}
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static size_t foug_stream_buffer_write(void* cookie,
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const void* ptr,
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size_t item_size,
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size_t item_count)
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{
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if (item_size > 0 && item_count > 0) {
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foug_buffer_t* buff = (foug_buffer_t*)cookie;
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const size_t buff_remaining_size = buff->len - buff->pos;
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const size_t wanted_write_size = item_size * item_count;
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const size_t next_write_size = wanted_write_size <= buff_remaining_size ? wanted_write_size :
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buff_remaining_size;
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const size_t next_write_item_count = next_write_size / item_size;
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memcpy((char*)buff->ptr + buff->pos, ptr, next_write_item_count * item_size);
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buff->pos += next_write_item_count * item_size;
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return next_write_item_count;
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}
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else {
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return 0;
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}
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}
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void foug_stream_set_buffer(foug_stream_t *stream, foug_buffer_t *buff)
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{
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stream->cookie = buff;
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stream->at_end_func = foug_stream_buffer_at_end;
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stream->error_func = foug_stream_buffer_error;
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stream->read_func = foug_stream_buffer_read;
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stream->write_func = foug_stream_buffer_write;
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}
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