Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

1 files changed, 365 insertions, 0 deletions

diff --git a/vcs-svn/fast_export.c b/vcs-svn/fast_export.c
new file mode 100644
index 000000000000..b5b8913cb0f2
--- /dev/null
+++ b/vcs-svn/fast_export.c
@@ -0,0 +1,365 @@
+/*
+ * 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);
+}