Edit

thodg/got/lib/fileindex.c

Branch :

  • Show log

    Commit

  • Author : Stefan Sperling
    Date : 2019-02-05 17:46:58
    Hash : c7f4312f
    Message : make 'got status' work in subdirectories of a work tree

  • lib/fileindex.c
  • /*
     * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
     *
     * Permission to use, copy, modify, and distribute this software for any
     * purpose with or without fee is hereby granted, provided that the above
     * copyright notice and this permission notice appear in all copies.
     *
     * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     */
    
    #include <sys/queue.h>
    #include <sys/tree.h>
    #include <sys/stat.h>
    
    #include <dirent.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sha1.h>
    #include <endian.h>
    #include <limits.h>
    
    #include "got_error.h"
    #include "got_object.h"
    
    #include "got_lib_path.h"
    #include "got_lib_fileindex.h"
    #include "got_lib_worktree.h"
    
    struct got_fileindex {
    	struct got_fileindex_tree entries;
    	int nentries;
    #define GOT_FILEIDX_MAX_ENTRIES INT_MAX
    };
    
    const struct got_error *
    got_fileindex_entry_update(struct got_fileindex_entry *entry,
        const char *ondisk_path, uint8_t *blob_sha1, uint8_t *commit_sha1)
    {
    	struct stat sb;
    
    	if (lstat(ondisk_path, &sb) != 0)
    		return got_error_from_errno();
    
    	entry->ctime_sec = sb.st_ctime;
    	entry->ctime_nsec = sb.st_ctimensec;
    	entry->mtime_sec = sb.st_mtime;
    	entry->mtime_nsec = sb.st_mtimensec;
    	entry->uid = sb.st_uid;
    	entry->gid = sb.st_gid;
    	entry->size = (sb.st_size & 0xffffffff);
    	if (sb.st_mode & S_IFLNK)
    		entry->mode = GOT_FILEIDX_MODE_SYMLINK;
    	else
    		entry->mode = GOT_FILEIDX_MODE_REGULAR_FILE;
    	entry->mode |= ((sb.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO)) <<
    	    GOT_FILEIDX_MODE_PERMS_SHIFT);
    	memcpy(entry->blob_sha1, blob_sha1, SHA1_DIGEST_LENGTH);
    	memcpy(entry->commit_sha1, commit_sha1, SHA1_DIGEST_LENGTH);
    
    	return NULL;
    }
    
    const struct got_error *
    got_fileindex_entry_alloc(struct got_fileindex_entry **entry,
        const char *ondisk_path, const char *relpath, uint8_t *blob_sha1,
        uint8_t *commit_sha1)
    {
    	size_t len;
    
    	*entry = calloc(1, sizeof(**entry));
    	if (*entry == NULL)
    		return got_error_from_errno();
    
    	(*entry)->path = strdup(relpath);
    	if ((*entry)->path == NULL) {
    		const struct got_error *err = got_error_from_errno();
    		free(*entry);
    		*entry = NULL;
    		return err;
    	}
    
    	len = strlen(relpath);
    	if (len > GOT_FILEIDX_F_PATH_LEN)
    		len = GOT_FILEIDX_F_PATH_LEN;
    	(*entry)->flags |= len;
    
    	return got_fileindex_entry_update(*entry, ondisk_path, blob_sha1,
    	    commit_sha1);
    }
    
    void
    got_fileindex_entry_free(struct got_fileindex_entry *entry)
    {
    	free(entry->path);
    	free(entry);
    }
    
    static const struct got_error *
    add_entry(struct got_fileindex *fileindex, struct got_fileindex_entry *entry)
    {
    	if (fileindex->nentries >= GOT_FILEIDX_MAX_ENTRIES)
    		return got_error(GOT_ERR_NO_SPACE);
    
    	RB_INSERT(got_fileindex_tree, &fileindex->entries, entry);
    	fileindex->nentries++;
    	return NULL;
    }
    
    const struct got_error *
    got_fileindex_entry_add(struct got_fileindex *fileindex,
        struct got_fileindex_entry *entry)
    {
    	/* Flag this entry until it gets written out to disk. */
    	entry->flags |= GOT_FILEIDX_F_INTENT_TO_ADD;
    
    	return add_entry(fileindex, entry);
    }
    
    void
    got_fileindex_entry_remove(struct got_fileindex *fileindex,
        struct got_fileindex_entry *entry)
    {
    	RB_REMOVE(got_fileindex_tree, &fileindex->entries, entry);
    	fileindex->nentries--;
    }
    
    struct got_fileindex_entry *
    got_fileindex_entry_get(struct got_fileindex *fileindex, const char *path)
    {
    	struct got_fileindex_entry key;
    	memset(&key, 0, sizeof(key));
    	key.path = (char *)path;
    	return RB_FIND(got_fileindex_tree, &fileindex->entries, &key);
    }
    
    const struct got_error *
    got_fileindex_for_each_entry_safe(struct got_fileindex *fileindex,
        got_fileindex_cb cb, void *cb_arg)
    {
    	const struct got_error *err;
    	struct got_fileindex_entry *entry, *tmp;
    
    	RB_FOREACH_SAFE(entry, got_fileindex_tree, &fileindex->entries, tmp) {
    		err = (*cb)(cb_arg, entry);
    		if (err)
    			return err;
    	}
    	return NULL;
    }
    
    struct got_fileindex *
    got_fileindex_alloc(void)
    {
    	struct got_fileindex *fileindex;
    
    	fileindex = calloc(1, sizeof(*fileindex));
    	if (fileindex == NULL)
    		return NULL;
    
    	RB_INIT(&fileindex->entries);
    	return fileindex;
    }
    
    void
    got_fileindex_free(struct got_fileindex *fileindex)
    {
    	struct got_fileindex_entry *entry;
    
    	while ((entry = RB_MIN(got_fileindex_tree, &fileindex->entries))) {
    		RB_REMOVE(got_fileindex_tree, &fileindex->entries, entry);
    		got_fileindex_entry_free(entry);
    	}
    	free(fileindex);
    }
    
    static const struct got_error *
    write_fileindex_val64(SHA1_CTX *ctx, uint64_t val, FILE *outfile)
    {
    	size_t n;
    
    	val = htobe64(val);
    	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
    	n = fwrite(&val, 1, sizeof(val), outfile);
    	if (n != sizeof(val))
    		return got_ferror(outfile, GOT_ERR_IO);
    	return NULL;
    }
    
    static const struct got_error *
    write_fileindex_val32(SHA1_CTX *ctx, uint32_t val, FILE *outfile)
    {
    	size_t n;
    
    	val = htobe32(val);
    	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
    	n = fwrite(&val, 1, sizeof(val), outfile);
    	if (n != sizeof(val))
    		return got_ferror(outfile, GOT_ERR_IO);
    	return NULL;
    }
    
    static const struct got_error *
    write_fileindex_val16(SHA1_CTX *ctx, uint16_t val, FILE *outfile)
    {
    	size_t n;
    
    	val = htobe16(val);
    	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
    	n = fwrite(&val, 1, sizeof(val), outfile);
    	if (n != sizeof(val))
    		return got_ferror(outfile, GOT_ERR_IO);
    	return NULL;
    }
    
    static const struct got_error *
    write_fileindex_path(SHA1_CTX *ctx, const char *path, FILE *outfile)
    {
    	size_t n, len, pad = 0;
    	static const uint8_t zero[8] = { 0 };
    
    	len = strlen(path);
    	while ((len + pad) % 8 != 0)
    		pad++;
    	if (pad == 0)
    		pad = 8; /* NUL-terminate */
    
    	SHA1Update(ctx, path, len);
    	n = fwrite(path, 1, len, outfile);
    	if (n != len)
    		return got_ferror(outfile, GOT_ERR_IO);
    	SHA1Update(ctx, zero, pad);
    	n = fwrite(zero, 1, pad, outfile);
    	if (n != pad)
    		return got_ferror(outfile, GOT_ERR_IO);
    	return NULL;
    }
    
    static const struct got_error *
    write_fileindex_entry(SHA1_CTX *ctx, struct got_fileindex_entry *entry,
        FILE *outfile)
    {
    	const struct got_error *err;
    	size_t n;
    
    	err = write_fileindex_val64(ctx, entry->ctime_sec, outfile);
    	if (err)
    		return err;
    	err = write_fileindex_val64(ctx, entry->ctime_nsec, outfile);
    	if (err)
    		return err;
    	err = write_fileindex_val64(ctx, entry->mtime_sec, outfile);
    	if (err)
    		return err;
    	err = write_fileindex_val64(ctx, entry->mtime_nsec, outfile);
    	if (err)
    		return err;
    
    	err = write_fileindex_val32(ctx, entry->uid, outfile);
    	if (err)
    		return err;
    	err = write_fileindex_val32(ctx, entry->gid, outfile);
    	if (err)
    		return err;
    	err = write_fileindex_val32(ctx, entry->size, outfile);
    	if (err)
    		return err;
    
    	err = write_fileindex_val16(ctx, entry->mode, outfile);
    	if (err)
    		return err;
    
    	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
    	n = fwrite(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
    	if (n != SHA1_DIGEST_LENGTH)
    		return got_ferror(outfile, GOT_ERR_IO);
    
    	SHA1Update(ctx, entry->commit_sha1, SHA1_DIGEST_LENGTH);
    	n = fwrite(entry->commit_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
    	if (n != SHA1_DIGEST_LENGTH)
    		return got_ferror(outfile, GOT_ERR_IO);
    
    	err = write_fileindex_val32(ctx, entry->flags, outfile);
    	if (err)
    		return err;
    
    	err = write_fileindex_path(ctx, entry->path, outfile);
    	return err;
    }
    
    const struct got_error *
    got_fileindex_write(struct got_fileindex *fileindex, FILE *outfile)
    {
    	const struct got_error *err = NULL;
    	struct got_fileindex_hdr hdr;
    	SHA1_CTX ctx;
    	uint8_t sha1[SHA1_DIGEST_LENGTH];
    	size_t n;
    	struct got_fileindex_entry *entry;
    
    	SHA1Init(&ctx);
    
    	hdr.signature = htobe32(GOT_FILE_INDEX_SIGNATURE);
    	hdr.version = htobe32(GOT_FILE_INDEX_VERSION);
    	hdr.nentries = htobe32(fileindex->nentries);
    
    	SHA1Update(&ctx, (uint8_t *)&hdr.signature, sizeof(hdr.signature));
    	SHA1Update(&ctx, (uint8_t *)&hdr.version, sizeof(hdr.version));
    	SHA1Update(&ctx, (uint8_t *)&hdr.nentries, sizeof(hdr.nentries));
    	n = fwrite(&hdr.signature, 1, sizeof(hdr.signature), outfile);
    	if (n != sizeof(hdr.signature))
    		return got_ferror(outfile, GOT_ERR_IO);
    	n = fwrite(&hdr.version, 1, sizeof(hdr.version), outfile);
    	if (n != sizeof(hdr.version))
    		return got_ferror(outfile, GOT_ERR_IO);
    	n = fwrite(&hdr.nentries, 1, sizeof(hdr.nentries), outfile);
    	if (n != sizeof(hdr.nentries))
    		return got_ferror(outfile, GOT_ERR_IO);
    
    	RB_FOREACH(entry, got_fileindex_tree, &fileindex->entries) {
    		entry->flags &= ~GOT_FILEIDX_F_INTENT_TO_ADD;
    		err = write_fileindex_entry(&ctx, entry, outfile);
    		if (err)
    			return err;
    	}
    
    	SHA1Final(sha1, &ctx);
    	n = fwrite(sha1, 1, sizeof(sha1), outfile);
    	if (n != sizeof(sha1))
    		return got_ferror(outfile, GOT_ERR_IO);
    
    	if (fflush(outfile) != 0)
    		return got_error_from_errno();
    
    	return NULL;
    }
    
    static const struct got_error *
    read_fileindex_val64(uint64_t *val, SHA1_CTX *ctx, FILE *infile)
    {
    	size_t n;
    
    	n = fread(val, 1, sizeof(*val), infile);
    	if (n != sizeof(*val))
    		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
    	*val = be64toh(*val);
    	return NULL;
    }
    
    static const struct got_error *
    read_fileindex_val32(uint32_t *val, SHA1_CTX *ctx, FILE *infile)
    {
    	size_t n;
    
    	n = fread(val, 1, sizeof(*val), infile);
    	if (n != sizeof(*val))
    		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
    	*val = be32toh(*val);
    	return NULL;
    }
    
    static const struct got_error *
    read_fileindex_val16(uint16_t *val, SHA1_CTX *ctx, FILE *infile)
    {
    	size_t n;
    
    	n = fread(val, 1, sizeof(*val), infile);
    	if (n != sizeof(*val))
    		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
    	*val = be16toh(*val);
    	return NULL;
    }
    
    static const struct got_error *
    read_fileindex_path(char **path, SHA1_CTX *ctx, FILE *infile)
    {
    	const struct got_error *err = NULL;
    	uint8_t buf[8];
    	size_t n, len = 0, totlen = sizeof(buf);
    
    	*path = malloc(totlen);
    	if (*path == NULL)
    		return got_error_from_errno();
    
    	do {
    		n = fread(buf, 1, sizeof(buf), infile);
    		if (n != sizeof(buf))
    			return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    		if (len + sizeof(buf) > totlen) {
    			char *p = reallocarray(*path, totlen + sizeof(buf), 1);
    			if (p == NULL) {
    				err = got_error_from_errno();
    				break;
    			}
    			totlen += sizeof(buf);
    			*path = p;
    		}
    		SHA1Update(ctx, buf, sizeof(buf));
    		memcpy(*path + len, buf, sizeof(buf));
    		len += sizeof(buf);
    	} while (memchr(buf, '\0', sizeof(buf)) == NULL);
    
    	if (err) {
    		free(*path);
    		*path = NULL;
    	}
    	return err;
    }
    
    static const struct got_error *
    read_fileindex_entry(struct got_fileindex_entry **entryp, SHA1_CTX *ctx,
        FILE *infile)
    {
    	const struct got_error *err;
    	struct got_fileindex_entry *entry;
    	size_t n;
    
    	*entryp = NULL;
    
    	entry = calloc(1, sizeof(*entry));
    	if (entry == NULL)
    		return got_error_from_errno();
    
    	err = read_fileindex_val64(&entry->ctime_sec, ctx, infile);
    	if (err)
    		goto done;
    	err = read_fileindex_val64(&entry->ctime_nsec, ctx, infile);
    	if (err)
    		goto done;
    	err = read_fileindex_val64(&entry->mtime_sec, ctx, infile);
    	if (err)
    		goto done;
    	err = read_fileindex_val64(&entry->mtime_nsec, ctx, infile);
    	if (err)
    		goto done;
    
    	err = read_fileindex_val32(&entry->uid, ctx, infile);
    	if (err)
    		goto done;
    	err = read_fileindex_val32(&entry->gid, ctx, infile);
    	if (err)
    		goto done;
    	err = read_fileindex_val32(&entry->size, ctx, infile);
    	if (err)
    		goto done;
    
    	err = read_fileindex_val16(&entry->mode, ctx, infile);
    	if (err)
    		goto done;
    
    	n = fread(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, infile);
    	if (n != SHA1_DIGEST_LENGTH) {
    		err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    		goto done;
    	}
    	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
    
    	n = fread(entry->commit_sha1, 1, SHA1_DIGEST_LENGTH, infile);
    	if (n != SHA1_DIGEST_LENGTH) {
    		err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    		goto done;
    	}
    	SHA1Update(ctx, entry->commit_sha1, SHA1_DIGEST_LENGTH);
    
    	err = read_fileindex_val32(&entry->flags, ctx, infile);
    	if (err)
    		goto done;
    
    	err = read_fileindex_path(&entry->path, ctx, infile);
    done:
    	if (err)
    		free(entry);
    	else
    		*entryp = entry;
    	return err;
    }
    
    const struct got_error *
    got_fileindex_read(struct got_fileindex *fileindex, FILE *infile)
    {
    	const struct got_error *err = NULL;
    	struct got_fileindex_hdr hdr;
    	SHA1_CTX ctx;
    	struct got_fileindex_entry *entry;
    	uint8_t sha1_expected[SHA1_DIGEST_LENGTH];
    	uint8_t sha1[SHA1_DIGEST_LENGTH];
    	size_t n;
    	int i;
    
    	SHA1Init(&ctx);
    
    	n = fread(&hdr.signature, 1, sizeof(hdr.signature), infile);
    	if (n != sizeof(hdr.signature)) {
    		if (n == 0) /* EOF */
    			return NULL;
    		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    	}
    	n = fread(&hdr.version, 1, sizeof(hdr.version), infile);
    	if (n != sizeof(hdr.version)) {
    		if (n == 0) /* EOF */
    			return NULL;
    		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    	}
    	n = fread(&hdr.nentries, 1, sizeof(hdr.nentries), infile);
    	if (n != sizeof(hdr.nentries)) {
    		if (n == 0) /* EOF */
    			return NULL;
    		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    	}
    
    	SHA1Update(&ctx, (uint8_t *)&hdr.signature, sizeof(hdr.signature));
    	SHA1Update(&ctx, (uint8_t *)&hdr.version, sizeof(hdr.version));
    	SHA1Update(&ctx, (uint8_t *)&hdr.nentries, sizeof(hdr.nentries));
    
    	hdr.signature = be32toh(hdr.signature);
    	hdr.version = be32toh(hdr.version);
    	hdr.nentries = be32toh(hdr.nentries);
    
    	if (hdr.signature != GOT_FILE_INDEX_SIGNATURE)
    		return got_error(GOT_ERR_FILEIDX_SIG);
    	if (hdr.version != GOT_FILE_INDEX_VERSION)
    		return got_error(GOT_ERR_FILEIDX_VER);
    
    	for (i = 0; i < hdr.nentries; i++) {
    		err = read_fileindex_entry(&entry, &ctx, infile);
    		if (err)
    			return err;
    		err = add_entry(fileindex, entry);
    		if (err)
    			return err;
    	}
    
    	n = fread(sha1_expected, 1, sizeof(sha1_expected), infile);
    	if (n != sizeof(sha1_expected))
    		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
    	SHA1Final(sha1, &ctx);
    	if (memcmp(sha1, sha1_expected, SHA1_DIGEST_LENGTH) != 0)
    		return got_error(GOT_ERR_FILEIDX_CSUM);
    
    	return NULL;
    }
    
    struct got_fileindex_entry *
    walk_fileindex(struct got_fileindex *fileindex, struct got_fileindex_entry *ie)
    {
    	struct got_fileindex_entry *next;
    
    	next = RB_NEXT(got_fileindex_tree, &fileindex->entries, ie);
    
    	/* Skip entries which were newly added by diff callbacks. */
    	while (next && (next->flags & GOT_FILEIDX_F_INTENT_TO_ADD))
    		next = RB_NEXT(got_fileindex_tree, &fileindex->entries, next);
    
    	return next;
    }
    
    static const struct got_error *
    diff_fileindex_tree(struct got_fileindex *, struct got_fileindex_entry **,
        struct got_tree_object *, const char *, struct got_repository *,
        struct got_fileindex_diff_tree_cb *, void *);
    
    static const struct got_error *
    walk_tree(struct got_tree_entry **next, struct got_fileindex *fileindex,
        struct got_fileindex_entry **ie, struct got_tree_entry *te,
        const char *path, struct got_repository *repo,
        struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
    {
    	const struct got_error *err = NULL;
    
    	if (S_ISDIR(te->mode)) {
    		char *subpath;
    		struct got_tree_object *subtree;
    
    		if (asprintf(&subpath, "%s%s%s", path,
    		    path[0] == '\0' ? "" : "/", te->name) == -1)
    			return got_error_from_errno();
    
    		err = got_object_open_as_tree(&subtree, repo, te->id);
    		if (err) {
    			free(subpath);
    			return err;
    		}
    
    		err = diff_fileindex_tree(fileindex, ie, subtree,
    		    subpath, repo, cb, cb_arg);
    		free(subpath);
    		got_object_tree_close(subtree);
    		if (err)
    			return err;
    	}
    
    	*next = SIMPLEQ_NEXT(te, entry);
    	return NULL;
    }
    
    /*
     * Decide whether a fileindex entry path is equivalent to a tree entry path,
     * and if it is not, then decide which of the two should be processed first.
     */
    static int
    cmp_entries(const char *ie_path, const char *parent_path,
        size_t parent_len, const char *te_name)
    {
    	int cmp = strncmp(ie_path, parent_path, parent_len);
    	if (cmp == 0) {
    		const char *ie_name = ie_path + parent_len;
    		while (ie_name[0] == '/')
    			ie_name++;
    		cmp = strcmp(ie_name, te_name);
    	}
    	return cmp;
    
    }
    
    static const struct got_error *
    diff_fileindex_tree(struct got_fileindex *fileindex,
        struct got_fileindex_entry **ie, struct got_tree_object *tree,
        const char *path, struct got_repository *repo,
        struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
    {
    	const struct got_error *err = NULL;
    	struct got_tree_entry *te = NULL;
    	size_t path_len = strlen(path);
    	const struct got_tree_entries *entries;
    	struct got_fileindex_entry *next;
    
    	entries = got_object_tree_get_entries(tree);
    	te = SIMPLEQ_FIRST(&entries->head);
    	while ((*ie && got_path_is_child((*ie)->path, path, path_len)) || te) {
    		if (te && *ie) {
    			int cmp = cmp_entries((*ie)->path, path, path_len,
    			    te->name);
    			if (cmp == 0) {
    				err = cb->diff_old_new(cb_arg, *ie, te,
    				    path);
    				if (err)
    					break;
    				*ie = walk_fileindex(fileindex, *ie);
    				err = walk_tree(&te, fileindex, ie, te,
    				    path, repo, cb, cb_arg);
    			} else if (cmp < 0 ) {
    				next = walk_fileindex(fileindex, *ie);
    				err = cb->diff_old(cb_arg, *ie, path);
    				if (err)
    					break;
    				*ie = next;
    			} else {
    				err = cb->diff_new(cb_arg, te, path);
    				if (err)
    					break;
    				err = walk_tree(&te, fileindex, ie, te,
    				    path, repo, cb, cb_arg);
    			}
    			if (err)
    				break;
    		} else if (*ie) {
    			next = walk_fileindex(fileindex, *ie);
    			err = cb->diff_old(cb_arg, *ie, path);
    			if (err)
    				break;
    			*ie = next;
    		} else if (te) {
    			err = cb->diff_new(cb_arg, te, path);
    			if (err)
    				break;
    			err = walk_tree(&te, fileindex, ie, te, path, repo, cb,
    			    cb_arg);
    			if (err)
    				break;
    		}
    	}
    
    	return err;
    }
    
    const struct got_error *
    got_fileindex_diff_tree(struct got_fileindex *fileindex,
        struct got_tree_object *tree, struct got_repository *repo,
        struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
    {
    	struct got_fileindex_entry *min;
    	min = RB_MIN(got_fileindex_tree, &fileindex->entries);
    	return diff_fileindex_tree(fileindex, &min, tree, "", repo, cb, cb_arg);
    }
    
    static const struct got_error *
    diff_fileindex_dir(struct got_fileindex *, struct got_fileindex_entry **, DIR *,
        const char *, const char *, struct got_repository *,
        struct got_fileindex_diff_dir_cb *, void *);
    
    static const struct got_error *
    walk_dir(struct got_pathlist_entry **next, struct got_fileindex *fileindex,
        struct got_fileindex_entry **ie, struct got_pathlist_entry *dle,
        const char *path, DIR *dir, const char *rootpath,
        struct got_repository *repo, struct got_fileindex_diff_dir_cb *cb,
        void *cb_arg)
    {
    	const struct got_error *err = NULL;
    	struct dirent *de = dle->data;
    
    	if (de->d_type == DT_DIR) {
    		char *subpath;
    		char *subdirpath;
    		DIR *subdir;
    
    		if (asprintf(&subpath, "%s%s%s", path,
    		    path[0] == '\0' ? "" : "/", de->d_name) == -1)
    			return got_error_from_errno();
    
    		if (asprintf(&subdirpath, "%s/%s", rootpath, subpath) == -1) {
    			free(subpath);
    			return got_error_from_errno();
    		}
    
    		subdir = opendir(subdirpath);
    		if (subdir == NULL) {
    			#if 0
    			free(subpath);
    			free(subdirpath);
    			#endif
    			return got_error_from_errno();
    		}
    
    		err = diff_fileindex_dir(fileindex, ie, subdir, rootpath,
    		    subpath, repo, cb, cb_arg);
    		free(subpath);
    		free(subdirpath);
    		closedir(subdir);
    		if (err)
    			return err;
    	}
    
    	*next = TAILQ_NEXT(dle, entry);
    	return NULL;
    }
    
    static const struct got_error *
    diff_fileindex_dir(struct got_fileindex *fileindex,
        struct got_fileindex_entry **ie, DIR *dir, const char *rootpath,
        const char *path, struct got_repository *repo,
        struct got_fileindex_diff_dir_cb *cb, void *cb_arg)
    {
    	const struct got_error *err = NULL;
    	struct dirent *de = NULL;
    	size_t path_len = strlen(path);
    	struct got_fileindex_entry *next;
    	struct got_pathlist_head dirlist;
    	struct got_pathlist_entry *dle;
    
    	TAILQ_INIT(&dirlist);
    
    	while (1) {
    		struct got_pathlist_entry *new = NULL;
    		struct dirent *dep = NULL;
    
    		de = malloc(sizeof(struct dirent) + NAME_MAX + 1);
    		if (de == NULL) {
    			err = got_error_from_errno();
    			goto done;
    		}
    
    		if (readdir_r(dir, de, &dep) != 0) {
    			err = got_error_from_errno();
    			free(de);
    			goto done;
    		}
    		if (dep == NULL) {
    			free(de);
    			break;
    		}
    
    		if (strcmp(de->d_name, ".") == 0 ||
    		    strcmp(de->d_name, "..") == 0 ||
    		    (path[0] == '\0' &&
    		    strcmp(de->d_name, GOT_WORKTREE_GOT_DIR) == 0)) {
    			free(de);
    			continue;
    		}
    
    		err = got_pathlist_insert(&new, &dirlist, de->d_name, de);
    		if (err)
    			goto done;
    		if (new == NULL) {
    			err = got_error(GOT_ERR_DIR_DUP_ENTRY);
    			goto done;
    		}
    	}
    
    	dle = TAILQ_FIRST(&dirlist);
    	while ((*ie && got_path_is_child((*ie)->path, path, path_len)) || dle) {
    		if (dle && *ie) {
    			int cmp;
    			de = dle->data;
    			cmp = cmp_entries((*ie)->path, path, path_len,
    			    de->d_name);
    			if (cmp == 0) {
    				err = cb->diff_old_new(cb_arg, *ie, de, path);
    				if (err)
    					break;
    				*ie = walk_fileindex(fileindex, *ie);
    				err = walk_dir(&dle, fileindex, ie, dle, path,
    				    dir, rootpath, repo, cb, cb_arg);
    			} else if (cmp < 0 ) {
    				next = walk_fileindex(fileindex, *ie);
    				err = cb->diff_old(cb_arg, *ie, path);
    				if (err)
    					break;
    				*ie = next;
    			} else {
    				err = cb->diff_new(cb_arg, de, path);
    				if (err)
    					break;
    				err = walk_dir(&dle, fileindex, ie, dle, path,
    				    dir, rootpath, repo, cb, cb_arg);
    			}
    			if (err)
    				break;
    		} else if (*ie) {
    			next = walk_fileindex(fileindex, *ie);
    			err = cb->diff_old(cb_arg, *ie, path);
    			if (err)
    				break;
    			*ie = next;
    		} else if (dle) {
    			de = dle->data;
    			err = cb->diff_new(cb_arg, de, path);
    			if (err)
    				break;
    			err = walk_dir(&dle, fileindex, ie, dle, path, dir,
    			    rootpath, repo, cb, cb_arg);
    			if (err)
    				break;
    		}
    	}
    done:
    	TAILQ_FOREACH(dle, &dirlist, entry)
    		free(dle->data);
    	got_pathlist_free(&dirlist);
    	return err;
    }
    
    const struct got_error *
    got_fileindex_diff_dir(struct got_fileindex *fileindex, DIR *rootdir,
        const char *rootpath, struct got_repository *repo,
        struct got_fileindex_diff_dir_cb *cb, void *cb_arg)
    {
    	struct got_fileindex_entry *min;
    	min = RB_MIN(got_fileindex_tree, &fileindex->entries);
    	return diff_fileindex_dir(fileindex, &min, rootdir, rootpath, "",
    	    repo, cb, cb_arg);
    }
    
    RB_GENERATE(got_fileindex_tree, got_fileindex_entry, entry, got_fileindex_cmp);