git/vcs-svn/fast_export.c
Florian Achleitner 8e43a1d010 remote-svn: add incremental import
Search for a note attached to the ref to update and read it's
'Revision-number:'-line. Start import from the next svn revision.

If there is no next revision in the svn repo, svnrdump terminates with
a message on stderr an non-zero return value. This looks a little
weird, but there is no other way to know whether there is a new
revision in the svn repo.

On the start of an incremental import, the parent of the first commit
in the fast-import stream is set to the branch name to update. All
following commits specify their parent by a mark number. Previous mark
files are currently not reused.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-07 14:10:17 -07:00

340 lines
9.2 KiB
C

/*
* Licensed under a two-clause BSD-style license.
* See LICENSE for details.
*/
#include "cache.h"
#include "quote.h"
#include "fast_export.h"
#include "repo_tree.h"
#include "strbuf.h"
#include "svndiff.h"
#include "sliding_window.h"
#include "line_buffer.h"
#define MAX_GITSVN_LINE_LEN 4096
static uint32_t first_commit_done;
static struct line_buffer postimage = LINE_BUFFER_INIT;
static struct line_buffer report_buffer = LINE_BUFFER_INIT;
/* NEEDSWORK: move to fast_export_init() */
static int init_postimage(void)
{
static int postimage_initialized;
if (postimage_initialized)
return 0;
postimage_initialized = 1;
return buffer_tmpfile_init(&postimage);
}
void fast_export_init(int fd)
{
first_commit_done = 0;
if (buffer_fdinit(&report_buffer, fd))
die_errno("cannot read from file descriptor %d", fd);
}
void fast_export_deinit(void)
{
if (buffer_deinit(&report_buffer))
die_errno("error closing fast-import feedback stream");
}
void fast_export_delete(const char *path)
{
putchar('D');
putchar(' ');
quote_c_style(path, NULL, stdout, 0);
putchar('\n');
}
static void fast_export_truncate(const char *path, uint32_t mode)
{
fast_export_modify(path, mode, "inline");
printf("data 0\n\n");
}
void fast_export_modify(const char *path, uint32_t mode, const char *dataref)
{
/* Mode must be 100644, 100755, 120000, or 160000. */
if (!dataref) {
fast_export_truncate(path, mode);
return;
}
printf("M %06"PRIo32" %s ", mode, dataref);
quote_c_style(path, NULL, stdout, 0);
putchar('\n');
}
void fast_export_begin_note(uint32_t revision, const char *author,
const char *log, unsigned long timestamp, const char *note_ref)
{
static int firstnote = 1;
size_t loglen = strlen(log);
printf("commit %s\n", note_ref);
printf("committer %s <%s@%s> %ld +0000\n", author, author, "local", timestamp);
printf("data %"PRIuMAX"\n", (uintmax_t)loglen);
fwrite(log, loglen, 1, stdout);
if (firstnote) {
if (revision > 1)
printf("from %s^0", note_ref);
firstnote = 0;
}
fputc('\n', stdout);
}
void fast_export_note(const char *committish, const char *dataref)
{
printf("N %s %s\n", dataref, committish);
}
static char gitsvnline[MAX_GITSVN_LINE_LEN];
void fast_export_begin_commit(uint32_t revision, const char *author,
const struct strbuf *log,
const char *uuid, const char *url,
unsigned long timestamp, const char *local_ref)
{
static const struct strbuf empty = STRBUF_INIT;
if (!log)
log = &empty;
if (*uuid && *url) {
snprintf(gitsvnline, MAX_GITSVN_LINE_LEN,
"\n\ngit-svn-id: %s@%"PRIu32" %s\n",
url, revision, uuid);
} else {
*gitsvnline = '\0';
}
printf("commit %s\n", local_ref);
printf("mark :%"PRIu32"\n", revision);
printf("committer %s <%s@%s> %ld +0000\n",
*author ? author : "nobody",
*author ? author : "nobody",
*uuid ? uuid : "local", timestamp);
printf("data %"PRIuMAX"\n",
(uintmax_t) (log->len + strlen(gitsvnline)));
fwrite(log->buf, log->len, 1, stdout);
printf("%s\n", gitsvnline);
if (!first_commit_done) {
if (revision > 1)
printf("from :%"PRIu32"\n", revision - 1);
first_commit_done = 1;
}
}
void fast_export_end_commit(uint32_t revision)
{
printf("progress Imported commit %"PRIu32".\n\n", revision);
}
static void ls_from_rev(uint32_t rev, const char *path)
{
/* ls :5 path/to/old/file */
printf("ls :%"PRIu32" ", rev);
quote_c_style(path, NULL, stdout, 0);
putchar('\n');
fflush(stdout);
}
static void ls_from_active_commit(const char *path)
{
/* ls "path/to/file" */
printf("ls \"");
quote_c_style(path, NULL, stdout, 1);
printf("\"\n");
fflush(stdout);
}
static const char *get_response_line(void)
{
const char *line = buffer_read_line(&report_buffer);
if (line)
return line;
if (buffer_ferror(&report_buffer))
die_errno("error reading from fast-import");
die("unexpected end of fast-import feedback");
}
static void die_short_read(struct line_buffer *input)
{
if (buffer_ferror(input))
die_errno("error reading dump file");
die("invalid dump: unexpected end of file");
}
static int ends_with(const char *s, size_t len, const char *suffix)
{
const size_t suffixlen = strlen(suffix);
if (len < suffixlen)
return 0;
return !memcmp(s + len - suffixlen, suffix, suffixlen);
}
static int parse_cat_response_line(const char *header, off_t *len)
{
size_t headerlen = strlen(header);
uintmax_t n;
const char *type;
const char *end;
if (ends_with(header, headerlen, " missing"))
return error("cat-blob reports missing blob: %s", header);
type = strstr(header, " blob ");
if (!type)
return error("cat-blob header has wrong object type: %s", header);
n = strtoumax(type + strlen(" blob "), (char **) &end, 10);
if (end == type + strlen(" blob "))
return error("cat-blob header does not contain length: %s", header);
if (memchr(type + strlen(" blob "), '-', end - type - strlen(" blob ")))
return error("cat-blob header contains negative length: %s", header);
if (n == UINTMAX_MAX || n > maximum_signed_value_of_type(off_t))
return error("blob too large for current definition of off_t");
*len = n;
if (*end)
return error("cat-blob header contains garbage after length: %s", header);
return 0;
}
static void check_preimage_overflow(off_t a, off_t b)
{
if (signed_add_overflows(a, b))
die("blob too large for current definition of off_t");
}
static long apply_delta(off_t len, struct line_buffer *input,
const char *old_data, uint32_t old_mode)
{
long ret;
struct sliding_view preimage = SLIDING_VIEW_INIT(&report_buffer, 0);
FILE *out;
if (init_postimage() || !(out = buffer_tmpfile_rewind(&postimage)))
die("cannot open temporary file for blob retrieval");
if (old_data) {
const char *response;
printf("cat-blob %s\n", old_data);
fflush(stdout);
response = get_response_line();
if (parse_cat_response_line(response, &preimage.max_off))
die("invalid cat-blob response: %s", response);
check_preimage_overflow(preimage.max_off, 1);
}
if (old_mode == REPO_MODE_LNK) {
strbuf_addstr(&preimage.buf, "link ");
check_preimage_overflow(preimage.max_off, strlen("link "));
preimage.max_off += strlen("link ");
check_preimage_overflow(preimage.max_off, 1);
}
if (svndiff0_apply(input, len, &preimage, out))
die("cannot apply delta");
if (old_data) {
/* Read the remainder of preimage and trailing newline. */
assert(!signed_add_overflows(preimage.max_off, 1));
preimage.max_off++; /* room for newline */
if (move_window(&preimage, preimage.max_off - 1, 1))
die("cannot seek to end of input");
if (preimage.buf.buf[0] != '\n')
die("missing newline after cat-blob response");
}
ret = buffer_tmpfile_prepare_to_read(&postimage);
if (ret < 0)
die("cannot read temporary file for blob retrieval");
strbuf_release(&preimage.buf);
return ret;
}
void fast_export_buf_to_data(const struct strbuf *data)
{
printf("data %"PRIuMAX"\n", (uintmax_t)data->len);
fwrite(data->buf, data->len, 1, stdout);
fputc('\n', stdout);
}
void fast_export_data(uint32_t mode, off_t len, struct line_buffer *input)
{
assert(len >= 0);
if (mode == REPO_MODE_LNK) {
/* svn symlink blobs start with "link " */
if (len < 5)
die("invalid dump: symlink too short for \"link\" prefix");
len -= 5;
if (buffer_skip_bytes(input, 5) != 5)
die_short_read(input);
}
printf("data %"PRIuMAX"\n", (uintmax_t) len);
if (buffer_copy_bytes(input, len) != len)
die_short_read(input);
fputc('\n', stdout);
}
static int parse_ls_response(const char *response, uint32_t *mode,
struct strbuf *dataref)
{
const char *tab;
const char *response_end;
assert(response);
response_end = response + strlen(response);
if (*response == 'm') { /* Missing. */
errno = ENOENT;
return -1;
}
/* Mode. */
if (response_end - response < (signed) strlen("100644") ||
response[strlen("100644")] != ' ')
die("invalid ls response: missing mode: %s", response);
*mode = 0;
for (; *response != ' '; response++) {
char ch = *response;
if (ch < '0' || ch > '7')
die("invalid ls response: mode is not octal: %s", response);
*mode *= 8;
*mode += ch - '0';
}
/* ' blob ' or ' tree ' */
if (response_end - response < (signed) strlen(" blob ") ||
(response[1] != 'b' && response[1] != 't'))
die("unexpected ls response: not a tree or blob: %s", response);
response += strlen(" blob ");
/* Dataref. */
tab = memchr(response, '\t', response_end - response);
if (!tab)
die("invalid ls response: missing tab: %s", response);
strbuf_add(dataref, response, tab - response);
return 0;
}
int fast_export_ls_rev(uint32_t rev, const char *path,
uint32_t *mode, struct strbuf *dataref)
{
ls_from_rev(rev, path);
return parse_ls_response(get_response_line(), mode, dataref);
}
int fast_export_ls(const char *path, uint32_t *mode, struct strbuf *dataref)
{
ls_from_active_commit(path);
return parse_ls_response(get_response_line(), mode, dataref);
}
void fast_export_blob_delta(uint32_t mode,
uint32_t old_mode, const char *old_data,
off_t len, struct line_buffer *input)
{
long postimage_len;
assert(len >= 0);
postimage_len = apply_delta(len, input, old_data, old_mode);
if (mode == REPO_MODE_LNK) {
buffer_skip_bytes(&postimage, strlen("link "));
postimage_len -= strlen("link ");
}
printf("data %ld\n", postimage_len);
buffer_copy_bytes(&postimage, postimage_len);
fputc('\n', stdout);
}