gmio/tests/stream_buffer.c
2016-01-26 17:03:58 +01:00

140 lines
4.5 KiB
C

/****************************************************************************
** gmio
** Copyright Fougue (2 Mar. 2015)
** contact@fougue.pro
**
** This software is a reusable library whose purpose is to provide complete
** I/O support for various CAD file formats (eg. STL)
**
** This software is governed by the CeCILL-B license under French law and
** abiding by the rules of distribution of free software. You can use,
** modify and/ or redistribute the software under the terms of the CeCILL-B
** license as circulated by CEA, CNRS and INRIA at the following URL
** "http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.html".
****************************************************************************/
#include "stream_buffer.h"
#include <string.h>
static bool gmio_stream_buffer_at_end(void* cookie)
{
const struct gmio_ro_buffer* buff = (const struct gmio_ro_buffer*)cookie;
return buff->pos >= buff->len;
}
static int gmio_stream_buffer_error(void* cookie)
{
const struct gmio_ro_buffer* buff = (const struct gmio_ro_buffer*)cookie;
return buff == NULL || buff->pos > buff->len;
}
static size_t gmio_stream_buffer_read(
void* cookie, void* ptr, size_t item_size, size_t item_count)
{
if (item_size > 0 && item_count > 0) {
struct gmio_ro_buffer* buff = (struct gmio_ro_buffer*)cookie;
const void* buff_ptr = buff->ptr;
const size_t buff_remaining_size = buff->len - buff->pos;
const size_t wanted_read_size = item_size * item_count;
const size_t next_read_size =
wanted_read_size <= buff_remaining_size ?
wanted_read_size :
buff_remaining_size;
const size_t next_read_item_count = next_read_size / item_size;
memcpy(ptr,
(const char*)buff_ptr + buff->pos,
next_read_item_count * item_size);
buff->pos += next_read_item_count * item_size;
return next_read_item_count;
}
else {
return 0;
}
}
static size_t gmio_stream_buffer_write(
void* cookie, const void* ptr, size_t item_size, size_t item_count)
{
if (item_size > 0 && item_count > 0) {
struct gmio_rw_buffer* buff = (struct gmio_rw_buffer*)cookie;
const size_t buff_remaining_size = buff->len - buff->pos;
const size_t wanted_write_size = item_size * item_count;
const size_t next_write_size =
wanted_write_size <= buff_remaining_size ?
wanted_write_size :
buff_remaining_size;
const size_t next_write_item_count = next_write_size / item_size;
memcpy((char*)buff->ptr + buff->pos,
ptr,
next_write_item_count * item_size);
buff->pos += next_write_item_count * item_size;
return next_write_item_count;
}
else {
return 0;
}
}
static gmio_streamsize_t gmio_stream_buffer_size(void* cookie)
{
const struct gmio_ro_buffer* buff = (const struct gmio_ro_buffer*)cookie;
return buff->len;
}
static int gmio_stream_buffer_get_pos(void* cookie, struct gmio_streampos* pos)
{
struct gmio_ro_buffer* buff = (struct gmio_ro_buffer*)cookie;
memcpy(&pos->cookie[0], &buff->pos, sizeof(size_t));
return 0;
}
static int gmio_stream_buffer_set_pos(
void* cookie, const struct gmio_streampos* pos)
{
struct gmio_ro_buffer* buff = (struct gmio_ro_buffer*)cookie;
memcpy(&buff->pos, &pos->cookie[0], sizeof(size_t));
return 0;
}
struct gmio_stream gmio_istream_buffer(struct gmio_ro_buffer* buff)
{
struct gmio_stream stream = {0};
stream.cookie = buff;
stream.func_at_end = gmio_stream_buffer_at_end;
stream.func_error = gmio_stream_buffer_error;
stream.func_read = gmio_stream_buffer_read;
stream.func_size = gmio_stream_buffer_size;
stream.func_get_pos = gmio_stream_buffer_get_pos;
stream.func_set_pos = gmio_stream_buffer_set_pos;
return stream;
}
struct gmio_stream gmio_stream_buffer(struct gmio_rw_buffer* buff)
{
struct gmio_stream stream =
gmio_istream_buffer((struct gmio_ro_buffer*)buff);
stream.func_write = gmio_stream_buffer_write;
return stream;
}
struct gmio_ro_buffer gmio_ro_buffer(const void *ptr, size_t len, size_t pos)
{
struct gmio_ro_buffer buff = {0};
buff.ptr = ptr;
buff.len = len;
buff.pos = pos;
return buff;
}
struct gmio_rw_buffer gmio_rw_buffer(void *ptr, size_t len, size_t pos)
{
struct gmio_rw_buffer buff = {0};
buff.ptr = ptr;
buff.len = len;
buff.pos = pos;
return buff;
}