mirror of
https://github.com/git/git
synced 2024-08-25 10:45:59 +00:00
git-pack-objects: write the pack files with a SHA1 csum
We want to be able to check their integrity later, and putting the sha1-sum of the contents at the end is a good thing. The writing routines are generic, so we could try to re-use them for the index file, instead of having the same logic duplicated. Update unpack-objects to know about the extra 20 bytes at the end of the index.
This commit is contained in:
parent
9b66ec0474
commit
c38138cd78
4
Makefile
4
Makefile
|
@ -45,9 +45,9 @@ install: $(PROG) $(SCRIPTS)
|
|||
|
||||
LIB_OBJS=read-cache.o sha1_file.o usage.o object.o commit.o tree.o blob.o \
|
||||
tag.o delta.o date.o index.o diff-delta.o patch-delta.o entry.o \
|
||||
epoch.o refs.o
|
||||
epoch.o refs.o csum-file.o
|
||||
LIB_FILE=libgit.a
|
||||
LIB_H=cache.h object.h blob.h tree.h commit.h tag.h delta.h epoch.h
|
||||
LIB_H=cache.h object.h blob.h tree.h commit.h tag.h delta.h epoch.h csum-file.h
|
||||
|
||||
LIB_H += strbuf.h
|
||||
LIB_OBJS += strbuf.o
|
||||
|
|
120
csum-file.c
Normal file
120
csum-file.c
Normal file
|
@ -0,0 +1,120 @@
|
|||
/*
|
||||
* 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 int sha1flush(struct sha1file *f, unsigned int count)
|
||||
{
|
||||
void *buf = f->buffer;
|
||||
|
||||
for (;;) {
|
||||
int ret = write(f->fd, buf, count);
|
||||
if (ret > 0) {
|
||||
buf += ret;
|
||||
count -= ret;
|
||||
if (count)
|
||||
continue;
|
||||
return 0;
|
||||
}
|
||||
if (!ret)
|
||||
die("sha1 file write error. Out of diskspace");
|
||||
if (errno == EAGAIN || errno == EINTR)
|
||||
continue;
|
||||
die("sha1 file write error (%s)", strerror(errno));
|
||||
}
|
||||
}
|
||||
|
||||
int sha1close(struct sha1file *f)
|
||||
{
|
||||
unsigned offset = f->offset;
|
||||
if (offset) {
|
||||
SHA1_Update(&f->ctx, f->buffer, offset);
|
||||
sha1flush(f, offset);
|
||||
}
|
||||
SHA1_Final(f->buffer, &f->ctx);
|
||||
sha1flush(f, 20);
|
||||
return 0;
|
||||
}
|
||||
|
||||
int sha1write(struct sha1file *f, void *buf, unsigned int 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;
|
||||
left -= nr;
|
||||
if (!left) {
|
||||
SHA1_Update(&f->ctx, f->buffer, offset);
|
||||
sha1flush(f, offset);
|
||||
offset = 0;
|
||||
}
|
||||
f->offset = offset;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
struct sha1file *sha1create(const char *fmt, ...)
|
||||
{
|
||||
static char filename[PATH_MAX];
|
||||
struct sha1file *f;
|
||||
unsigned len;
|
||||
va_list arg;
|
||||
int fd;
|
||||
|
||||
va_start(arg, fmt);
|
||||
len = vsnprintf(filename, PATH_MAX, fmt, arg);
|
||||
va_end(arg);
|
||||
|
||||
if (len >= PATH_MAX)
|
||||
die("you wascally wabbit, you");
|
||||
fd = open(filename, O_CREAT | O_EXCL | O_WRONLY, 0644);
|
||||
if (fd < 0)
|
||||
die("unable to open %s (%s)", filename, strerror(errno));
|
||||
f = xmalloc(sizeof(*f));
|
||||
f->fd = fd;
|
||||
f->error = 0;
|
||||
f->offset = 0;
|
||||
SHA1_Init(&f->ctx);
|
||||
return f;
|
||||
}
|
||||
|
||||
int sha1write_compressed(struct sha1file *f, void *in, unsigned int size)
|
||||
{
|
||||
z_stream stream;
|
||||
unsigned long maxsize;
|
||||
void *out;
|
||||
|
||||
memset(&stream, 0, sizeof(stream));
|
||||
deflateInit(&stream, Z_DEFAULT_COMPRESSION);
|
||||
maxsize = deflateBound(&stream, size);
|
||||
out = xmalloc(maxsize);
|
||||
|
||||
/* Compress it */
|
||||
stream.next_in = in;
|
||||
stream.avail_in = size;
|
||||
|
||||
stream.next_out = out;
|
||||
stream.avail_out = maxsize;
|
||||
|
||||
while (deflate(&stream, Z_FINISH) == Z_OK)
|
||||
/* nothing */;
|
||||
deflateEnd(&stream);
|
||||
|
||||
size = stream.total_out;
|
||||
sha1write(f, out, size);
|
||||
free(out);
|
||||
return size;
|
||||
}
|
||||
|
||||
|
17
csum-file.h
Normal file
17
csum-file.h
Normal file
|
@ -0,0 +1,17 @@
|
|||
#ifndef CSUM_FILE_H
|
||||
#define CSUM_FILE_H
|
||||
|
||||
/* A SHA1-protected file */
|
||||
struct sha1file {
|
||||
int fd, error;
|
||||
unsigned long offset;
|
||||
SHA_CTX ctx;
|
||||
unsigned char buffer[8192];
|
||||
};
|
||||
|
||||
extern struct sha1file *sha1create(const char *fmt, ...);
|
||||
extern int sha1close(struct sha1file *);
|
||||
extern int sha1write(struct sha1file *, void *, unsigned int);
|
||||
extern int sha1write_compressed(struct sha1file *, void *, unsigned int);
|
||||
|
||||
#endif
|
|
@ -2,6 +2,7 @@
|
|||
#include "cache.h"
|
||||
#include "object.h"
|
||||
#include "delta.h"
|
||||
#include "csum-file.h"
|
||||
|
||||
static const char pack_usage[] = "git-pack-objects [--window=N] [--depth=N] base-name < object-list";
|
||||
|
||||
|
@ -29,51 +30,6 @@ static struct object_entry *objects = NULL;
|
|||
static int nr_objects = 0, nr_alloc = 0;
|
||||
static const char *base_name;
|
||||
|
||||
struct myfile {
|
||||
int fd;
|
||||
unsigned long chars;
|
||||
unsigned char buffer[8192];
|
||||
};
|
||||
|
||||
static FILE *create_file(const char *suffix)
|
||||
{
|
||||
static char filename[PATH_MAX];
|
||||
unsigned len;
|
||||
|
||||
len = snprintf(filename, PATH_MAX, "%s.%s", base_name, suffix);
|
||||
if (len >= PATH_MAX)
|
||||
die("you wascally wabbit, you");
|
||||
return fopen(filename, "w");
|
||||
}
|
||||
|
||||
static unsigned long fwrite_compressed(void *in, unsigned long size, FILE *f)
|
||||
{
|
||||
z_stream stream;
|
||||
unsigned long maxsize;
|
||||
void *out;
|
||||
|
||||
memset(&stream, 0, sizeof(stream));
|
||||
deflateInit(&stream, Z_DEFAULT_COMPRESSION);
|
||||
maxsize = deflateBound(&stream, size);
|
||||
out = xmalloc(maxsize);
|
||||
|
||||
/* Compress it */
|
||||
stream.next_in = in;
|
||||
stream.avail_in = size;
|
||||
|
||||
stream.next_out = out;
|
||||
stream.avail_out = maxsize;
|
||||
|
||||
while (deflate(&stream, Z_FINISH) == Z_OK)
|
||||
/* nothing */;
|
||||
deflateEnd(&stream);
|
||||
|
||||
size = stream.total_out;
|
||||
fwrite(out, size, 1, f);
|
||||
free(out);
|
||||
return size;
|
||||
}
|
||||
|
||||
static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
|
||||
{
|
||||
unsigned long othersize, delta_size;
|
||||
|
@ -92,7 +48,7 @@ static void *delta_against(void *buf, unsigned long size, struct object_entry *e
|
|||
return delta_buf;
|
||||
}
|
||||
|
||||
static unsigned long write_object(FILE *f, struct object_entry *entry)
|
||||
static unsigned long write_object(struct sha1file *f, struct object_entry *entry)
|
||||
{
|
||||
unsigned long size;
|
||||
char type[10];
|
||||
|
@ -121,8 +77,8 @@ static unsigned long write_object(FILE *f, struct object_entry *entry)
|
|||
}
|
||||
datalen = htonl(size);
|
||||
memcpy(header+1, &datalen, 4);
|
||||
fwrite(header, hdrlen, 1, f);
|
||||
datalen = fwrite_compressed(buf, size, f);
|
||||
sha1write(f, header, hdrlen);
|
||||
datalen = sha1write_compressed(f, buf, size);
|
||||
free(buf);
|
||||
return hdrlen + datalen;
|
||||
}
|
||||
|
@ -130,7 +86,7 @@ static unsigned long write_object(FILE *f, struct object_entry *entry)
|
|||
static void write_pack_file(void)
|
||||
{
|
||||
int i;
|
||||
FILE *f = create_file("pack");
|
||||
struct sha1file *f = sha1create("%s.%s", base_name, "pack");
|
||||
unsigned long offset = 0;
|
||||
unsigned long mb;
|
||||
|
||||
|
@ -139,7 +95,7 @@ static void write_pack_file(void)
|
|||
entry->offset = offset;
|
||||
offset += write_object(f, entry);
|
||||
}
|
||||
fclose(f);
|
||||
sha1close(f);
|
||||
mb = offset >> 20;
|
||||
offset &= 0xfffff;
|
||||
}
|
||||
|
@ -147,7 +103,7 @@ static void write_pack_file(void)
|
|||
static void write_index_file(void)
|
||||
{
|
||||
int i;
|
||||
FILE *f = create_file("idx");
|
||||
struct sha1file *f = sha1create("%s.%s", base_name, "idx");
|
||||
struct object_entry **list = sorted_by_sha;
|
||||
struct object_entry **last = list + nr_objects;
|
||||
unsigned int array[256];
|
||||
|
@ -168,7 +124,7 @@ static void write_index_file(void)
|
|||
array[i] = htonl(next - sorted_by_sha);
|
||||
list = next;
|
||||
}
|
||||
fwrite(array, 256, sizeof(int), f);
|
||||
sha1write(f, array, 256 * sizeof(int));
|
||||
|
||||
/*
|
||||
* Write the actual SHA1 entries..
|
||||
|
@ -177,10 +133,10 @@ static void write_index_file(void)
|
|||
for (i = 0; i < nr_objects; i++) {
|
||||
struct object_entry *entry = *list++;
|
||||
unsigned int offset = htonl(entry->offset);
|
||||
fwrite(&offset, 4, 1, f);
|
||||
fwrite(entry->sha1, 20, 1, f);
|
||||
sha1write(f, &offset, 4);
|
||||
sha1write(f, entry->sha1, 20);
|
||||
}
|
||||
fclose(f);
|
||||
sha1close(f);
|
||||
}
|
||||
|
||||
static void add_object_entry(unsigned char *sha1, unsigned int hash)
|
||||
|
|
|
@ -61,7 +61,7 @@ static int check_index(void)
|
|||
unsigned int nr;
|
||||
int i;
|
||||
|
||||
if (index_size < 4*256)
|
||||
if (index_size < 4*256 + 20)
|
||||
return error("index file too small");
|
||||
nr = 0;
|
||||
for (i = 0; i < 256; i++) {
|
||||
|
@ -70,11 +70,14 @@ static int check_index(void)
|
|||
return error("non-monotonic index");
|
||||
nr = n;
|
||||
}
|
||||
if (index_size != 4*256 + nr * 24) {
|
||||
printf("index_size=%lu, expected %u (%u)\n",
|
||||
index_size, 4*256 + nr * 24, nr);
|
||||
/*
|
||||
* Total size:
|
||||
* - 256 index entries 4 bytes each
|
||||
* - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
|
||||
* - 20-byte SHA1 file checksum
|
||||
*/
|
||||
if (index_size != 4*256 + nr * 24 + 20)
|
||||
return error("wrong index file size");
|
||||
}
|
||||
|
||||
nr_entries = nr;
|
||||
pack_list = xmalloc(nr * sizeof(struct pack_entry *));
|
||||
|
|
Loading…
Reference in a new issue