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/*
* csum-file.c
*
* Copyright (C) 2005 Linus Torvalds
*
* Simple file write infrastructure for writing SHA1-summed
* files. Useful when you write a file that you want to be
* able to verify hasn't been messed with afterwards.
*/
#include "cache.h"
#include "csum-file.h"
static void sha1flush(struct sha1file *f, unsigned int count)
{
void *buf = f->buffer;
for (;;) {
int ret = xwrite(f->fd, buf, count);
if (ret > 0) {
buf = (char *) buf + ret;
count -= ret;
if (count)
continue;
return;
}
if (!ret)
die("sha1 file '%s' write error. Out of diskspace", f->name);
die("sha1 file '%s' write error (%s)", f->name, strerror(errno));
}
}
int sha1close(struct sha1file *f, unsigned char *result, int final)
{
int fd;
unsigned offset = f->offset;
if (offset) {
SHA1_Update(&f->ctx, f->buffer, offset);
sha1flush(f, offset);
f->offset = 0;
}
if (final) {
/* write checksum and close fd */
SHA1_Final(f->buffer, &f->ctx);
if (result)
hashcpy(result, f->buffer);
sha1flush(f, 20);
if (close(f->fd))
die("%s: sha1 file error on close (%s)",
f->name, strerror(errno));
fd = 0;
} else
fd = f->fd;
free(f);
return fd;
}
int sha1write(struct sha1file *f, void *buf, unsigned int count)
{
if (f->do_crc)
f->crc32 = crc32(f->crc32, buf, count);
while (count) {
unsigned offset = f->offset;
unsigned left = sizeof(f->buffer) - offset;
unsigned nr = count > left ? left : count;
memcpy(f->buffer + offset, buf, nr);
count -= nr;
offset += nr;
buf = (char *) buf + nr;
left -= nr;
if (!left) {
SHA1_Update(&f->ctx, f->buffer, offset);
sha1flush(f, offset);
offset = 0;
}
f->offset = offset;
}
return 0;
}
struct sha1file *sha1fd(int fd, const char *name)
{
struct sha1file *f;
unsigned len;
f = xmalloc(sizeof(*f));
len = strlen(name);
if (len >= PATH_MAX)
die("you wascally wabbit, you");
f->namelen = len;
memcpy(f->name, name, len+1);
f->fd = fd;
f->error = 0;
f->offset = 0;
f->do_crc = 0;
SHA1_Init(&f->ctx);
return f;
}
void crc32_begin(struct sha1file *f)
{
f->crc32 = crc32(0, Z_NULL, 0);
f->do_crc = 1;
}
uint32_t crc32_end(struct sha1file *f)
{
f->do_crc = 0;
return f->crc32;
}
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