/*
* make sure tail is larger than sz
*/
size_t buf_readjust(buf_t *buf, size_t sz) {
while (buf->sz - buf->idx_write < sz) {
if (buf->idx_read < buf->sz / 2) {
buf_realloc(buf, buf->sz * 2);
} else {
buf_realloc(buf, buf->sz);
}
}
return buf->sz;
}
static int my_real_read(int fd, buf_t *buf, int *done)
{
int left, n;
uint32_t pktlen;
char *ptr;
ptr = buf->ptr;
*done = 0;
left = buf->size - buf->used;
ptr = buf->ptr + buf->used;
AGAIN:
if( (n = read(fd, ptr, left)) < 0 ){
if(errno == EINTR){
goto AGAIN;
} else if( errno == EAGAIN || errno == EWOULDBLOCK){
return 0 ;
} else {
return n;
}
} else if(n == 0) {//zero indicates end of file
info(g_log, "my_real_read failed, fd:%d, ret:%d, errno:%d, errmsg:%s\n", fd, n, errno, strerror(errno)) ;
return -1;
} else {
buf->used += n;
buf->pos += n;
if(buf->used >= HEADER_SIZE){
//如果已经读取到了4个字节的固定长度，那么就可以拿到数据包有多大了，也就是这次应该读取的长度是多少大
ptr = buf->ptr;
pktlen = 0;
memcpy(&pktlen, ptr, 3);
if((pktlen + HEADER_SIZE) > buf->size){//总大小是否超过了当前缓冲的大小，如果是需要重新申请一块大内存
if(buf_realloc(buf, pktlen + HEADER_SIZE) == NULL){
return -1;
}
}
if(buf->used >= (pktlen + HEADER_SIZE)){//读取完毕了
*done = 1;
}
}
return n;
}
return 0 ;
}
static bool page_begin(struct urf_context *ctx)
{
if (ctx->page_hdr->bpp != 24) {
URF_SET_ERROR(ctx, "unsupported bpp", -ctx->page_hdr->bpp);
return false;
}
IMPL(ctx)->zlen = 2 * deflateBound(&IMPL(ctx)->strm, ctx->page_line_bytes);
if (!buf_realloc(ctx, &IMPL(ctx)->zbuf, IMPL(ctx)->zlen)) {
return false;
}
IMPL(ctx)->idx = 0;
return xprintf(ctx,
"%%%%Page: %" PRIu32 " %" PRIu32 "\n"
"%%%%PageBoundingBox: 0 0 %" PRIu32 " %" PRIu32 "\n"
"save\n"
"/DeviceRGB setcolorspace\n"
"<<\n"
" /ImageType 1\n"
" /Width %" PRIu32 "\n"
" /Height %" PRIu32 "\n"
//" /ImageMatrix [ %" PRIu32 " 0 0 -%" PRIu32 " 0 %" PRIu32 " ]\n"
" /ImageMatrix [ 1 0 0 -1 0 %" PRIu32 " ]\n"
" /BitsPerComponent 8\n"
" /Interpolate true\n"
" /Decode [ 0 1 0 1 0 1 ]\n"
" /DataSource currentfile\n"
//" /ASCIIHexDecode filter\n"
#if ASCII85 == 1
" /ASCII85Decode filter\n"
#else
" /ASCIIHexDecode filter\n"
#endif
#ifndef NODEFLATE
" /FlateDecode filter\n"
#endif
">> image\n",
ctx->page_n, ctx->page_n, ctx->page_hdr->width,
ctx->page_hdr->height, ctx->page_hdr->width,
ctx->page_hdr->height,
// ctx->page_hdr->width, ctx->page_hdr->height,
ctx->page_hdr->height);
}
