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git/vcs-svn/line_buffer.c
Jonathan Nieder 896e4bfcec vcs-svn: make buffer_read_binary API more convenient
buffer_read_binary is a thin wrapper around fread, but its signature
is wrong:

 - fread can fill an arbitrary in-memory buffer.  buffer_read_binary
   is limited to buffers whose size is representable by a 32-bit
   integer.
 - The result from fread is the number of bytes actually read.
   buffer_read_binary only reports the number of bytes read by
   incrementing sb->len by that amount and returns void.

Fix both: let buffer_read_binary accept a size_t instead of uint32_t
for the number of bytes to read and as a convenience return the number
of bytes actually read.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-03-27 22:37:05 -05:00

130 lines
2.8 KiB
C

/*
* Licensed under a two-clause BSD-style license.
* See LICENSE for details.
*/
#include "git-compat-util.h"
#include "line_buffer.h"
#include "strbuf.h"
#define COPY_BUFFER_LEN 4096
int buffer_init(struct line_buffer *buf, const char *filename)
{
buf->infile = filename ? fopen(filename, "r") : stdin;
if (!buf->infile)
return -1;
return 0;
}
int buffer_fdinit(struct line_buffer *buf, int fd)
{
buf->infile = fdopen(fd, "r");
if (!buf->infile)
return -1;
return 0;
}
int buffer_tmpfile_init(struct line_buffer *buf)
{
buf->infile = tmpfile();
if (!buf->infile)
return -1;
return 0;
}
int buffer_deinit(struct line_buffer *buf)
{
int err;
if (buf->infile == stdin)
return ferror(buf->infile);
err = ferror(buf->infile);
err |= fclose(buf->infile);
return err;
}
FILE *buffer_tmpfile_rewind(struct line_buffer *buf)
{
rewind(buf->infile);
return buf->infile;
}
long buffer_tmpfile_prepare_to_read(struct line_buffer *buf)
{
long pos = ftell(buf->infile);
if (pos < 0)
return error("ftell error: %s", strerror(errno));
if (fseek(buf->infile, 0, SEEK_SET))
return error("seek error: %s", strerror(errno));
return pos;
}
int buffer_ferror(struct line_buffer *buf)
{
return ferror(buf->infile);
}
int buffer_read_char(struct line_buffer *buf)
{
return fgetc(buf->infile);
}
/* Read a line without trailing newline. */
char *buffer_read_line(struct line_buffer *buf)
{
char *end;
if (!fgets(buf->line_buffer, sizeof(buf->line_buffer), buf->infile))
/* Error or data exhausted. */
return NULL;
end = buf->line_buffer + strlen(buf->line_buffer);
if (end[-1] == '\n')
end[-1] = '\0';
else if (feof(buf->infile))
; /* No newline at end of file. That's fine. */
else
/*
* Line was too long.
* There is probably a saner way to deal with this,
* but for now let's return an error.
*/
return NULL;
return buf->line_buffer;
}
size_t buffer_read_binary(struct line_buffer *buf,
struct strbuf *sb, size_t size)
{
return strbuf_fread(sb, size, buf->infile);
}
off_t buffer_copy_bytes(struct line_buffer *buf, off_t nbytes)
{
char byte_buffer[COPY_BUFFER_LEN];
off_t done = 0;
while (done < nbytes && !feof(buf->infile) && !ferror(buf->infile)) {
off_t len = nbytes - done;
size_t in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
in = fread(byte_buffer, 1, in, buf->infile);
done += in;
fwrite(byte_buffer, 1, in, stdout);
if (ferror(stdout))
return done + buffer_skip_bytes(buf, nbytes - done);
}
return done;
}
off_t buffer_skip_bytes(struct line_buffer *buf, off_t nbytes)
{
char byte_buffer[COPY_BUFFER_LEN];
off_t done = 0;
while (done < nbytes && !feof(buf->infile) && !ferror(buf->infile)) {
off_t len = nbytes - done;
size_t in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
done += fread(byte_buffer, 1, in, buf->infile);
}
return done;
}
void buffer_reset(struct line_buffer *buf)
{
}