vcs-svn/fast_export.c - git - Git at Google

 /*
  * Licensed under a two-clause BSD-style license.
  * See LICENSE for details.
  */

 #include "cache.h"
 #include "quote.h"
 #include "fast_export.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, timestamp_t 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> %"PRItime" +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,
 			timestamp_t 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> %"PRItime" +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 parse_cat_response_line(const char *header, off_t *len)
 {
 	uintmax_t n;
 	const char *type;
 	const char *end;

 	if (ends_with(header, " 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 == S_IFLNK) {
 		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 == S_IFLNK) {
 		/* 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);
 }

 const char *fast_export_read_path(const char *path, uint32_t *mode_out)
 {
 	int err;
 	static struct strbuf buf = STRBUF_INIT;

 	strbuf_reset(&buf);
 	err = fast_export_ls(path, mode_out, &buf);
 	if (err) {
 		if (errno != ENOENT)
 			BUG("unexpected fast_export_ls error: %s",
 			    strerror(errno));
 		/* Treat missing paths as directories. */
 		*mode_out = S_IFDIR;
 		return NULL;
 	}
 	return buf.buf;
 }

 void fast_export_copy(uint32_t revision, const char *src, const char *dst)
 {
 	int err;
 	uint32_t mode;
 	static struct strbuf data = STRBUF_INIT;

 	strbuf_reset(&data);
 	err = fast_export_ls_rev(revision, src, &mode, &data);
 	if (err) {
 		if (errno != ENOENT)
 			BUG("unexpected fast_export_ls_rev error: %s",
 			    strerror(errno));
 		fast_export_delete(dst);
 		return;
 	}
 	fast_export_modify(dst, mode, data.buf);
 }

 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 == S_IFLNK) {
 		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);
 }
	/*
	* Licensed under a two-clause BSD-style license.
	* See LICENSE for details.
	*/

	#include "cache.h"
	#include "quote.h"
	#include "fast_export.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, timestamp_t 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> %"PRItime" +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,
	timestamp_t timestamp, const char *local_ref)
	{
	static const struct strbuf empty = STRBUF_INIT;
	if (!log)
	log = ∅
	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> %"PRItime" +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 parse_cat_response_line(const char header, off_t len)
	{
	uintmax_t n;
	const char *type;
	const char *end;

	if (ends_with(header, " 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 == S_IFLNK) {
	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 == S_IFLNK) {
	/* 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);
	}

	const char fast_export_read_path(const char path, uint32_t *mode_out)
	{
	int err;
	static struct strbuf buf = STRBUF_INIT;

	strbuf_reset(&buf);
	err = fast_export_ls(path, mode_out, &buf);
	if (err) {
	if (errno != ENOENT)
	BUG("unexpected fast_export_ls error: %s",
	strerror(errno));
	/* Treat missing paths as directories. */
	*mode_out = S_IFDIR;
	return NULL;
	}
	return buf.buf;
	}

	void fast_export_copy(uint32_t revision, const char src, const char dst)
	{
	int err;
	uint32_t mode;
	static struct strbuf data = STRBUF_INIT;

	strbuf_reset(&data);
	err = fast_export_ls_rev(revision, src, &mode, &data);
	if (err) {
	if (errno != ENOENT)
	BUG("unexpected fast_export_ls_rev error: %s",
	strerror(errno));
	fast_export_delete(dst);
	return;
	}
	fast_export_modify(dst, mode, data.buf);
	}

	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 == S_IFLNK) {
	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);
	}