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#include "mupdf/fitz/stream.h"
#include "mupdf/fitz/string.h"
#if defined(_WIN32) && !defined(NDEBUG)
#include "windows.h"
static void
show_progress(int av, int pos)
{
char text[80];
sprintf(text, "Have %d, Want %d\n", av, pos);
OutputDebugStringA(text);
}
#else
#define show_progress(A,B) do {} while (0)
#endif
/* File stream - progressive reading to simulate http download */
typedef struct prog_state
{
int fd;
int length;
int available;
int bps;
clock_t start_time;
unsigned char buffer[4096];
} prog_state;
static int next_prog(fz_stream *stm, int len)
{
prog_state *ps = (prog_state *)stm->state;
int n;
unsigned char *buf = ps->buffer;
if (len > sizeof(ps->buffer))
len = sizeof(ps->buffer);
/* Simulate more data having arrived */
if (ps->available < ps->length)
{
int av = (int)((float)(clock() - ps->start_time) * ps->bps / (CLOCKS_PER_SEC*8));
if (av > ps->length)
av = ps->length;
ps->available = av;
/* Limit any fetches to be within the data we have */
if (av < ps->length && len + stm->pos > av)
{
len = av - stm->pos;
if (len <= 0)
{
show_progress(av, stm->pos);
fz_throw(stm->ctx, FZ_ERROR_TRYLATER, "Not enough data yet");
}
}
}
n = (len > 0 ? read(ps->fd, buf, len) : 0);
if (n < 0)
fz_throw(stm->ctx, FZ_ERROR_GENERIC, "read error: %s", strerror(errno));
stm->rp = ps->buffer + stm->pos;
stm->wp = ps->buffer + stm->pos + n;
stm->pos += n;
if (n == 0)
return EOF;
return *stm->rp++;
}
static void seek_prog(fz_stream *stm, int offset, int whence)
{
prog_state *ps = (prog_state *)stm->state;
int n;
/* Simulate more data having arrived */
if (ps->available < ps->length)
{
int av = (int)((float)(clock() - ps->start_time) * ps->bps / (CLOCKS_PER_SEC*8));
if (av > ps->length)
av = ps->length;
ps->available = av;
}
if (ps->available < ps->length)
{
if (whence == SEEK_END)
{
show_progress(ps->available, ps->length);
fz_throw(stm->ctx, FZ_ERROR_TRYLATER, "Not enough data to seek to end yet");
}
}
if (whence == SEEK_CUR)
{
whence = SEEK_SET;
offset += stm->pos;
if (offset > ps->available)
{
show_progress(ps->available, offset);
fz_throw(stm->ctx, FZ_ERROR_TRYLATER, "Not enough data to seek (relatively) to offset yet");
}
}
if (whence == SEEK_SET)
{
if (offset > ps->available)
{
show_progress(ps->available, offset);
fz_throw(stm->ctx, FZ_ERROR_TRYLATER, "Not enough data to seek to offset yet");
}
}
n = lseek(ps->fd, offset, whence);
if (n < 0)
fz_throw(stm->ctx, FZ_ERROR_GENERIC, "cannot lseek: %s", strerror(errno));
stm->pos = n;
stm->wp = stm->rp;
}
static void close_prog(fz_context *ctx, void *state)
{
prog_state *ps = (prog_state *)state;
int n = close(ps->fd);
if (n < 0)
fz_warn(ctx, "close error: %s", strerror(errno));
fz_free(ctx, state);
}
static int meta_prog(fz_stream *stm, int key, int size, void *ptr)
{
prog_state *ps = (prog_state *)stm->state;
switch(key)
{
case FZ_STREAM_META_PROGRESSIVE:
return 1;
break;
case FZ_STREAM_META_LENGTH:
return ps->length;
}
return -1;
}
fz_stream *
fz_open_fd_progressive(fz_context *ctx, int fd, int bps)
{
fz_stream *stm;
prog_state *state;
state = fz_malloc_struct(ctx, prog_state);
state->fd = fd;
state->bps = bps;
state->start_time = clock();
state->available = 0;
state->length = lseek(state->fd, 0, SEEK_END);
lseek(state->fd, 0, SEEK_SET);
fz_try(ctx)
{
stm = fz_new_stream(ctx, state, next_prog, close_prog, NULL);
}
fz_catch(ctx)
{
fz_free(ctx, state);
fz_rethrow(ctx);
}
stm->seek = seek_prog;
stm->meta = meta_prog;
return stm;
}
fz_stream *
fz_open_file_progressive(fz_context *ctx, const char *name, int bps)
{
#ifdef _WIN32
char *s = (char*)name;
wchar_t *wname, *d;
int c, fd;
d = wname = fz_malloc(ctx, (strlen(name)+1) * sizeof(wchar_t));
while (*s) {
s += fz_chartorune(&c, s);
*d++ = c;
}
*d = 0;
fd = _wopen(wname, O_BINARY | O_RDONLY, 0);
fz_free(ctx, wname);
#else
int fd = open(name, O_BINARY | O_RDONLY, 0);
#endif
if (fd == -1)
fz_throw(ctx, FZ_ERROR_GENERIC, "cannot open %s", name);
return fz_open_fd_progressive(ctx, fd, bps);
}
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