Merge branch 'db/vcs-svn-incremental' into svn-fe

This teaches svn-fe to incrementally import into an existing
repository (at last!) at the expense of less convenient UI.  Think of
it as growing pains.  This opens the door to many excellent things,
and it would be a bad idea to discourage people from building on it
for much longer.

* db/vcs-svn-incremental:
  vcs-svn: avoid using ls command twice
  vcs-svn: use mark from previous import for parent commit
  vcs-svn: handle filenames with dq correctly
  vcs-svn: quote paths correctly for ls command
  vcs-svn: eliminate repo_tree structure
  vcs-svn: add a comment before each commit
  vcs-svn: save marks for imported commits
  vcs-svn: use higher mark numbers for blobs
  vcs-svn: set up channel to read fast-import cat-blob response

Conflicts:
	t/t9010-svn-fe.sh
	vcs-svn/fast_export.c
	vcs-svn/fast_export.h
	vcs-svn/repo_tree.c
	vcs-svn/svndump.c

1 files changed, 25 insertions, 303 deletions

diff --git a/vcs-svn/repo_tree.c b/vcs-svn/repo_tree.c
index a21d89d..1681b65 100644
--- a/vcs-svn/repo_tree.c
+++ b/vcs-svn/repo_tree.c
@@ -4,323 +4,45 @@
  */
 
 #include "git-compat-util.h"
-
-#include "string_pool.h"
+#include "strbuf.h"
 #include "repo_tree.h"
-#include "obj_pool.h"
 #include "fast_export.h"
 
-#include "trp.h"
-
-struct repo_dirent {
-	uint32_t name_offset;
-	struct trp_node children;
-	uint32_t mode;
-	uint32_t content_offset;
-};
-
-struct repo_dir {
-	struct trp_root entries;
-};
-
-struct repo_commit {
-	uint32_t root_dir_offset;
-};
-
-/* Memory pools for commit, dir and dirent */
-obj_pool_gen(commit, struct repo_commit, 4096)
-obj_pool_gen(dir, struct repo_dir, 4096)
-obj_pool_gen(dent, struct repo_dirent, 4096)
-
-static uint32_t active_commit;
-static uint32_t mark;
-
-static int repo_dirent_name_cmp(const void *a, const void *b);
-
-/* Treap for directory entries */
-trp_gen(static, dent_, struct repo_dirent, children, dent, repo_dirent_name_cmp)
-
-uint32_t next_blob_mark(void)
-{
-	return mark++;
-}
-
-static struct repo_dir *repo_commit_root_dir(struct repo_commit *commit)
-{
-	return dir_pointer(commit->root_dir_offset);
-}
-
-static struct repo_dirent *repo_first_dirent(struct repo_dir *dir)
-{
-	return dent_first(&dir->entries);
-}
-
-static int repo_dirent_name_cmp(const void *a, const void *b)
-{
-	const struct repo_dirent *dent1 = a, *dent2 = b;
-	uint32_t a_offset = dent1->name_offset;
-	uint32_t b_offset = dent2->name_offset;
-	return (a_offset > b_offset) - (a_offset < b_offset);
-}
-
-static int repo_dirent_is_dir(struct repo_dirent *dent)
+const char *repo_read_path(const uint32_t *path, uint32_t *mode_out)
 {
-	return dent != NULL && dent->mode == REPO_MODE_DIR;
-}
+	int err;
+	static struct strbuf buf = STRBUF_INIT;
 
-static struct repo_dir *repo_dir_from_dirent(struct repo_dirent *dent)
-{
-	if (!repo_dirent_is_dir(dent))
+	strbuf_reset(&buf);
+	err = fast_export_ls(REPO_MAX_PATH_DEPTH, path, mode_out, &buf);
+	if (err) {
+		if (errno != ENOENT)
+			die_errno("BUG: unexpected fast_export_ls error");
+		/* Treat missing paths as directories. */
+		*mode_out = REPO_MODE_DIR;
 		return NULL;
-	return dir_pointer(dent->content_offset);
-}
-
-static struct repo_dir *repo_clone_dir(struct repo_dir *orig_dir)
-{
-	uint32_t orig_o, new_o;
-	orig_o = dir_offset(orig_dir);
-	if (orig_o >= dir_pool.committed)
-		return orig_dir;
-	new_o = dir_alloc(1);
-	orig_dir = dir_pointer(orig_o);
-	*dir_pointer(new_o) = *orig_dir;
-	return dir_pointer(new_o);
-}
-
-static struct repo_dirent *repo_read_dirent(uint32_t revision,
-					    const uint32_t *path)
-{
-	uint32_t name = 0;
-	struct repo_dirent *key = dent_pointer(dent_alloc(1));
-	struct repo_dir *dir = NULL;
-	struct repo_dirent *dent = NULL;
-	dir = repo_commit_root_dir(commit_pointer(revision));
-	while (~(name = *path++)) {
-		key->name_offset = name;
-		dent = dent_search(&dir->entries, key);
-		if (dent == NULL || !repo_dirent_is_dir(dent))
-			break;
-		dir = repo_dir_from_dirent(dent);
 	}
-	dent_free(1);
-	return dent;
-}
-
-static void repo_write_dirent(const uint32_t *path, uint32_t mode,
-			      uint32_t content_offset, uint32_t del)
-{
-	uint32_t name, revision, dir_o = ~0, parent_dir_o = ~0;
-	struct repo_dir *dir;
-	struct repo_dirent *key;
-	struct repo_dirent *dent = NULL;
-	revision = active_commit;
-	dir = repo_commit_root_dir(commit_pointer(revision));
-	dir = repo_clone_dir(dir);
-	commit_pointer(revision)->root_dir_offset = dir_offset(dir);
-	while (~(name = *path++)) {
-		parent_dir_o = dir_offset(dir);
-
-		key = dent_pointer(dent_alloc(1));
-		key->name_offset = name;
-
-		dent = dent_search(&dir->entries, key);
-		if (dent == NULL)
-			dent = key;
-		else
-			dent_free(1);
-
-		if (dent == key) {
-			dent->mode = REPO_MODE_DIR;
-			dent->content_offset = 0;
-			dent = dent_insert(&dir->entries, dent);
-		}
-
-		if (dent_offset(dent) < dent_pool.committed) {
-			dir_o = repo_dirent_is_dir(dent) ?
-					dent->content_offset : ~0;
-			dent_remove(&dir->entries, dent);
-			dent = dent_pointer(dent_alloc(1));
-			dent->name_offset = name;
-			dent->mode = REPO_MODE_DIR;
-			dent->content_offset = dir_o;
-			dent = dent_insert(&dir->entries, dent);
-		}
-
-		dir = repo_dir_from_dirent(dent);
-		dir = repo_clone_dir(dir);
-		dent->content_offset = dir_offset(dir);
-	}
-	if (dent == NULL)
-		return;
-	dent->mode = mode;
-	dent->content_offset = content_offset;
-	if (del && ~parent_dir_o)
-		dent_remove(&dir_pointer(parent_dir_o)->entries, dent);
-}
-
-uint32_t repo_read_path(const uint32_t *path)
-{
-	uint32_t content_offset = 0;
-	struct repo_dirent *dent = repo_read_dirent(active_commit, path);
-	if (dent != NULL)
-		content_offset = dent->content_offset;
-	return content_offset;
-}
-
-uint32_t repo_read_mode(const uint32_t *path)
-{
-	struct repo_dirent *dent = repo_read_dirent(active_commit, path);
-	if (dent == NULL)
-		die("invalid dump: path to be modified is missing");
-	return dent->mode;
+	return buf.buf;
 }
 
 void repo_copy(uint32_t revision, const uint32_t *src, const uint32_t *dst)
 {
-	uint32_t mode = 0, content_offset = 0;
-	struct repo_dirent *src_dent;
-	src_dent = repo_read_dirent(revision, src);
-	if (src_dent != NULL) {
-		mode = src_dent->mode;
-		content_offset = src_dent->content_offset;
-		repo_write_dirent(dst, mode, content_offset, 0);
+	int err;
+	uint32_t mode;
+	static struct strbuf data = STRBUF_INIT;
+
+	strbuf_reset(&data);
+	err = fast_export_ls_rev(revision, REPO_MAX_PATH_DEPTH, src, &mode, &data);
+	if (err) {
+		if (errno != ENOENT)
+			die_errno("BUG: unexpected fast_export_ls_rev error");
+		fast_export_delete(REPO_MAX_PATH_DEPTH, dst);
+		return;
 	}
-}
-
-void repo_add(uint32_t *path, uint32_t mode, uint32_t blob_mark)
-{
-	repo_write_dirent(path, mode, blob_mark, 0);
+	fast_export_modify(REPO_MAX_PATH_DEPTH, dst, mode, data.buf);
 }
 
 void repo_delete(uint32_t *path)
 {
-	repo_write_dirent(path, 0, 0, 1);
-}
-
-static void repo_git_add_r(uint32_t depth, uint32_t *path, struct repo_dir *dir);
-
-static void repo_git_add(uint32_t depth, uint32_t *path, struct repo_dirent *dent)
-{
-	if (repo_dirent_is_dir(dent))
-		repo_git_add_r(depth, path, repo_dir_from_dirent(dent));
-	else
-		fast_export_modify(depth, path,
-				   dent->mode, dent->content_offset);
-}
-
-static void repo_git_add_r(uint32_t depth, uint32_t *path, struct repo_dir *dir)
-{
-	struct repo_dirent *de = repo_first_dirent(dir);
-	while (de) {
-		path[depth] = de->name_offset;
-		repo_git_add(depth + 1, path, de);
-		de = dent_next(&dir->entries, de);
-	}
-}
-
-static void repo_diff_r(uint32_t depth, uint32_t *path, struct repo_dir *dir1,
-			struct repo_dir *dir2)
-{
-	struct repo_dirent *de1, *de2;
-	de1 = repo_first_dirent(dir1);
-	de2 = repo_first_dirent(dir2);
-
-	while (de1 && de2) {
-		if (de1->name_offset < de2->name_offset) {
-			path[depth] = de1->name_offset;
-			fast_export_delete(depth + 1, path);
-			de1 = dent_next(&dir1->entries, de1);
-			continue;
-		}
-		if (de1->name_offset > de2->name_offset) {
-			path[depth] = de2->name_offset;
-			repo_git_add(depth + 1, path, de2);
-			de2 = dent_next(&dir2->entries, de2);
-			continue;
-		}
-		path[depth] = de1->name_offset;
-
-		if (de1->mode == de2->mode &&
-		    de1->content_offset == de2->content_offset) {
-			; /* No change. */
-		} else if (repo_dirent_is_dir(de1) && repo_dirent_is_dir(de2)) {
-			repo_diff_r(depth + 1, path,
-				    repo_dir_from_dirent(de1),
-				    repo_dir_from_dirent(de2));
-		} else if (!repo_dirent_is_dir(de1) && !repo_dirent_is_dir(de2)) {
-			repo_git_add(depth + 1, path, de2);
-		} else {
-			fast_export_delete(depth + 1, path);
-			repo_git_add(depth + 1, path, de2);
-		}
-		de1 = dent_next(&dir1->entries, de1);
-		de2 = dent_next(&dir2->entries, de2);
-	}
-	while (de1) {
-		path[depth] = de1->name_offset;
-		fast_export_delete(depth + 1, path);
-		de1 = dent_next(&dir1->entries, de1);
-	}
-	while (de2) {
-		path[depth] = de2->name_offset;
-		repo_git_add(depth + 1, path, de2);
-		de2 = dent_next(&dir2->entries, de2);
-	}
-}
-
-static uint32_t path_stack[REPO_MAX_PATH_DEPTH];
-
-void repo_diff(uint32_t r1, uint32_t r2)
-{
-	repo_diff_r(0,
-		    path_stack,
-		    repo_commit_root_dir(commit_pointer(r1)),
-		    repo_commit_root_dir(commit_pointer(r2)));
-}
-
-void repo_commit(uint32_t revision, const char *author,
-		const struct strbuf *log, const char *uuid, const char *url,
-		unsigned long timestamp)
-{
-	fast_export_commit(revision, author, log, uuid, url, timestamp);
-	dent_commit();
-	dir_commit();
-	active_commit = commit_alloc(1);
-	commit_pointer(active_commit)->root_dir_offset =
-		commit_pointer(active_commit - 1)->root_dir_offset;
-}
-
-static void mark_init(void)
-{
-	uint32_t i;
-	mark = 0;
-	for (i = 0; i < dent_pool.size; i++)
-		if (!repo_dirent_is_dir(dent_pointer(i)) &&
-		    dent_pointer(i)->content_offset > mark)
-			mark = dent_pointer(i)->content_offset;
-	mark++;
-}
-
-void repo_init(void)
-{
-	mark_init();
-	if (commit_pool.size == 0) {
-		/* Create empty tree for commit 0. */
-		commit_alloc(1);
-		commit_pointer(0)->root_dir_offset = dir_alloc(1);
-		dir_pointer(0)->entries.trp_root = ~0;
-		dir_commit();
-	}
-	/* Preallocate next commit, ready for changes. */
-	active_commit = commit_alloc(1);
-	commit_pointer(active_commit)->root_dir_offset =
-		commit_pointer(active_commit - 1)->root_dir_offset;
-}
-
-void repo_reset(void)
-{
-	pool_reset();
-	commit_reset();
-	dir_reset();
-	dent_reset();
+	fast_export_delete(REPO_MAX_PATH_DEPTH, path);
 }