diff options
Diffstat (limited to 'src/filebuf.c')
| -rw-r--r-- | src/filebuf.c | 595 |
1 files changed, 0 insertions, 595 deletions
diff --git a/src/filebuf.c b/src/filebuf.c deleted file mode 100644 index a3f6b1483..000000000 --- a/src/filebuf.c +++ /dev/null @@ -1,595 +0,0 @@ -/* - * Copyright (C) the libgit2 contributors. All rights reserved. - * - * This file is part of libgit2, distributed under the GNU GPL v2 with - * a Linking Exception. For full terms see the included COPYING file. - */ - -#include "filebuf.h" - -#include "futils.h" - -static const size_t WRITE_BUFFER_SIZE = (4096 * 2); - -enum buferr_t { - BUFERR_OK = 0, - BUFERR_WRITE, - BUFERR_ZLIB, - BUFERR_MEM -}; - -#define ENSURE_BUF_OK(buf) if ((buf)->last_error != BUFERR_OK) { return -1; } - -static int verify_last_error(git_filebuf *file) -{ - switch (file->last_error) { - case BUFERR_WRITE: - git_error_set(GIT_ERROR_OS, "failed to write out file"); - return -1; - - case BUFERR_MEM: - git_error_set_oom(); - return -1; - - case BUFERR_ZLIB: - git_error_set(GIT_ERROR_ZLIB, - "Buffer error when writing out ZLib data"); - return -1; - - default: - return 0; - } -} - -static int lock_file(git_filebuf *file, int flags, mode_t mode) -{ - if (git_path_exists(file->path_lock) == true) { - git_error_clear(); /* actual OS error code just confuses */ - git_error_set(GIT_ERROR_OS, - "failed to lock file '%s' for writing", file->path_lock); - return GIT_ELOCKED; - } - - /* create path to the file buffer is required */ - if (flags & GIT_FILEBUF_CREATE_LEADING_DIRS) { - /* XXX: Should dirmode here be configurable? Or is 0777 always fine? */ - file->fd = git_futils_creat_locked_withpath(file->path_lock, 0777, mode); - } else { - file->fd = git_futils_creat_locked(file->path_lock, mode); - } - - if (file->fd < 0) - return file->fd; - - file->fd_is_open = true; - - if ((flags & GIT_FILEBUF_APPEND) && git_path_exists(file->path_original) == true) { - git_file source; - char buffer[FILEIO_BUFSIZE]; - ssize_t read_bytes; - int error = 0; - - source = p_open(file->path_original, O_RDONLY); - if (source < 0) { - git_error_set(GIT_ERROR_OS, - "failed to open file '%s' for reading", - file->path_original); - return -1; - } - - while ((read_bytes = p_read(source, buffer, sizeof(buffer))) > 0) { - if ((error = p_write(file->fd, buffer, read_bytes)) < 0) - break; - if (file->compute_digest) - git_hash_update(&file->digest, buffer, read_bytes); - } - - p_close(source); - - if (read_bytes < 0) { - git_error_set(GIT_ERROR_OS, "failed to read file '%s'", file->path_original); - return -1; - } else if (error < 0) { - git_error_set(GIT_ERROR_OS, "failed to write file '%s'", file->path_lock); - return -1; - } - } - - return 0; -} - -void git_filebuf_cleanup(git_filebuf *file) -{ - if (file->fd_is_open && file->fd >= 0) - p_close(file->fd); - - if (file->created_lock && !file->did_rename && file->path_lock && git_path_exists(file->path_lock)) - p_unlink(file->path_lock); - - if (file->compute_digest) { - git_hash_ctx_cleanup(&file->digest); - file->compute_digest = 0; - } - - if (file->buffer) - git__free(file->buffer); - - /* use the presence of z_buf to decide if we need to deflateEnd */ - if (file->z_buf) { - git__free(file->z_buf); - deflateEnd(&file->zs); - } - - if (file->path_original) - git__free(file->path_original); - if (file->path_lock) - git__free(file->path_lock); - - memset(file, 0x0, sizeof(git_filebuf)); - file->fd = -1; -} - -GIT_INLINE(int) flush_buffer(git_filebuf *file) -{ - int result = file->write(file, file->buffer, file->buf_pos); - file->buf_pos = 0; - return result; -} - -int git_filebuf_flush(git_filebuf *file) -{ - return flush_buffer(file); -} - -static int write_normal(git_filebuf *file, void *source, size_t len) -{ - if (len > 0) { - if (p_write(file->fd, (void *)source, len) < 0) { - file->last_error = BUFERR_WRITE; - return -1; - } - - if (file->compute_digest) - git_hash_update(&file->digest, source, len); - } - - return 0; -} - -static int write_deflate(git_filebuf *file, void *source, size_t len) -{ - z_stream *zs = &file->zs; - - if (len > 0 || file->flush_mode == Z_FINISH) { - zs->next_in = source; - zs->avail_in = (uInt)len; - - do { - size_t have; - - zs->next_out = file->z_buf; - zs->avail_out = (uInt)file->buf_size; - - if (deflate(zs, file->flush_mode) == Z_STREAM_ERROR) { - file->last_error = BUFERR_ZLIB; - return -1; - } - - have = file->buf_size - (size_t)zs->avail_out; - - if (p_write(file->fd, file->z_buf, have) < 0) { - file->last_error = BUFERR_WRITE; - return -1; - } - - } while (zs->avail_out == 0); - - GIT_ASSERT(zs->avail_in == 0); - - if (file->compute_digest) - git_hash_update(&file->digest, source, len); - } - - return 0; -} - -#define MAX_SYMLINK_DEPTH 5 - -static int resolve_symlink(git_buf *out, const char *path) -{ - int i, error, root; - ssize_t ret; - struct stat st; - git_buf curpath = GIT_BUF_INIT, target = GIT_BUF_INIT; - - if ((error = git_buf_grow(&target, GIT_PATH_MAX + 1)) < 0 || - (error = git_buf_puts(&curpath, path)) < 0) - return error; - - for (i = 0; i < MAX_SYMLINK_DEPTH; i++) { - error = p_lstat(curpath.ptr, &st); - if (error < 0 && errno == ENOENT) { - error = git_buf_puts(out, curpath.ptr); - goto cleanup; - } - - if (error < 0) { - git_error_set(GIT_ERROR_OS, "failed to stat '%s'", curpath.ptr); - error = -1; - goto cleanup; - } - - if (!S_ISLNK(st.st_mode)) { - error = git_buf_puts(out, curpath.ptr); - goto cleanup; - } - - ret = p_readlink(curpath.ptr, target.ptr, GIT_PATH_MAX); - if (ret < 0) { - git_error_set(GIT_ERROR_OS, "failed to read symlink '%s'", curpath.ptr); - error = -1; - goto cleanup; - } - - if (ret == GIT_PATH_MAX) { - git_error_set(GIT_ERROR_INVALID, "symlink target too long"); - error = -1; - goto cleanup; - } - - /* readlink(2) won't NUL-terminate for us */ - target.ptr[ret] = '\0'; - target.size = ret; - - root = git_path_root(target.ptr); - if (root >= 0) { - if ((error = git_buf_sets(&curpath, target.ptr)) < 0) - goto cleanup; - } else { - git_buf dir = GIT_BUF_INIT; - - if ((error = git_path_dirname_r(&dir, curpath.ptr)) < 0) - goto cleanup; - - git_buf_swap(&curpath, &dir); - git_buf_dispose(&dir); - - if ((error = git_path_apply_relative(&curpath, target.ptr)) < 0) - goto cleanup; - } - } - - git_error_set(GIT_ERROR_INVALID, "maximum symlink depth reached"); - error = -1; - -cleanup: - git_buf_dispose(&curpath); - git_buf_dispose(&target); - return error; -} - -int git_filebuf_open(git_filebuf *file, const char *path, int flags, mode_t mode) -{ - return git_filebuf_open_withsize(file, path, flags, mode, WRITE_BUFFER_SIZE); -} - -int git_filebuf_open_withsize(git_filebuf *file, const char *path, int flags, mode_t mode, size_t size) -{ - int compression, error = -1; - size_t path_len, alloc_len; - - GIT_ASSERT_ARG(file); - GIT_ASSERT_ARG(path); - GIT_ASSERT(file->buffer == NULL); - - memset(file, 0x0, sizeof(git_filebuf)); - - if (flags & GIT_FILEBUF_DO_NOT_BUFFER) - file->do_not_buffer = true; - - if (flags & GIT_FILEBUF_FSYNC) - file->do_fsync = true; - - file->buf_size = size; - file->buf_pos = 0; - file->fd = -1; - file->last_error = BUFERR_OK; - - /* Allocate the main cache buffer */ - if (!file->do_not_buffer) { - file->buffer = git__malloc(file->buf_size); - GIT_ERROR_CHECK_ALLOC(file->buffer); - } - - /* If we are hashing on-write, allocate a new hash context */ - if (flags & GIT_FILEBUF_HASH_CONTENTS) { - file->compute_digest = 1; - - if (git_hash_ctx_init(&file->digest) < 0) - goto cleanup; - } - - compression = flags >> GIT_FILEBUF_DEFLATE_SHIFT; - - /* If we are deflating on-write, */ - if (compression != 0) { - /* Initialize the ZLib stream */ - if (deflateInit(&file->zs, compression) != Z_OK) { - git_error_set(GIT_ERROR_ZLIB, "failed to initialize zlib"); - goto cleanup; - } - - /* Allocate the Zlib cache buffer */ - file->z_buf = git__malloc(file->buf_size); - GIT_ERROR_CHECK_ALLOC(file->z_buf); - - /* Never flush */ - file->flush_mode = Z_NO_FLUSH; - file->write = &write_deflate; - } else { - file->write = &write_normal; - } - - /* If we are writing to a temp file */ - if (flags & GIT_FILEBUF_TEMPORARY) { - git_buf tmp_path = GIT_BUF_INIT; - - /* Open the file as temporary for locking */ - file->fd = git_futils_mktmp(&tmp_path, path, mode); - - if (file->fd < 0) { - git_buf_dispose(&tmp_path); - goto cleanup; - } - file->fd_is_open = true; - file->created_lock = true; - - /* No original path */ - file->path_original = NULL; - file->path_lock = git_buf_detach(&tmp_path); - GIT_ERROR_CHECK_ALLOC(file->path_lock); - } else { - git_buf resolved_path = GIT_BUF_INIT; - - if ((error = resolve_symlink(&resolved_path, path)) < 0) - goto cleanup; - - /* Save the original path of the file */ - path_len = resolved_path.size; - file->path_original = git_buf_detach(&resolved_path); - - /* create the locking path by appending ".lock" to the original */ - GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, path_len, GIT_FILELOCK_EXTLENGTH); - file->path_lock = git__malloc(alloc_len); - GIT_ERROR_CHECK_ALLOC(file->path_lock); - - memcpy(file->path_lock, file->path_original, path_len); - memcpy(file->path_lock + path_len, GIT_FILELOCK_EXTENSION, GIT_FILELOCK_EXTLENGTH); - - if (git_path_isdir(file->path_original)) { - git_error_set(GIT_ERROR_FILESYSTEM, "path '%s' is a directory", file->path_original); - error = GIT_EDIRECTORY; - goto cleanup; - } - - /* open the file for locking */ - if ((error = lock_file(file, flags, mode)) < 0) - goto cleanup; - - file->created_lock = true; - } - - return 0; - -cleanup: - git_filebuf_cleanup(file); - return error; -} - -int git_filebuf_hash(git_oid *oid, git_filebuf *file) -{ - GIT_ASSERT_ARG(oid); - GIT_ASSERT_ARG(file); - GIT_ASSERT_ARG(file->compute_digest); - - flush_buffer(file); - - if (verify_last_error(file) < 0) - return -1; - - git_hash_final(oid, &file->digest); - git_hash_ctx_cleanup(&file->digest); - file->compute_digest = 0; - - return 0; -} - -int git_filebuf_commit_at(git_filebuf *file, const char *path) -{ - git__free(file->path_original); - file->path_original = git__strdup(path); - GIT_ERROR_CHECK_ALLOC(file->path_original); - - return git_filebuf_commit(file); -} - -int git_filebuf_commit(git_filebuf *file) -{ - /* temporary files cannot be committed */ - GIT_ASSERT_ARG(file); - GIT_ASSERT(file->path_original); - - file->flush_mode = Z_FINISH; - flush_buffer(file); - - if (verify_last_error(file) < 0) - goto on_error; - - file->fd_is_open = false; - - if (file->do_fsync && p_fsync(file->fd) < 0) { - git_error_set(GIT_ERROR_OS, "failed to fsync '%s'", file->path_lock); - goto on_error; - } - - if (p_close(file->fd) < 0) { - git_error_set(GIT_ERROR_OS, "failed to close file at '%s'", file->path_lock); - goto on_error; - } - - file->fd = -1; - - if (p_rename(file->path_lock, file->path_original) < 0) { - git_error_set(GIT_ERROR_OS, "failed to rename lockfile to '%s'", file->path_original); - goto on_error; - } - - if (file->do_fsync && git_futils_fsync_parent(file->path_original) < 0) - goto on_error; - - file->did_rename = true; - - git_filebuf_cleanup(file); - return 0; - -on_error: - git_filebuf_cleanup(file); - return -1; -} - -GIT_INLINE(void) add_to_cache(git_filebuf *file, const void *buf, size_t len) -{ - memcpy(file->buffer + file->buf_pos, buf, len); - file->buf_pos += len; -} - -int git_filebuf_write(git_filebuf *file, const void *buff, size_t len) -{ - const unsigned char *buf = buff; - - ENSURE_BUF_OK(file); - - if (file->do_not_buffer) - return file->write(file, (void *)buff, len); - - for (;;) { - size_t space_left = file->buf_size - file->buf_pos; - - /* cache if it's small */ - if (space_left > len) { - add_to_cache(file, buf, len); - return 0; - } - - add_to_cache(file, buf, space_left); - if (flush_buffer(file) < 0) - return -1; - - len -= space_left; - buf += space_left; - } -} - -int git_filebuf_reserve(git_filebuf *file, void **buffer, size_t len) -{ - size_t space_left = file->buf_size - file->buf_pos; - - *buffer = NULL; - - ENSURE_BUF_OK(file); - - if (len > file->buf_size) { - file->last_error = BUFERR_MEM; - return -1; - } - - if (space_left <= len) { - if (flush_buffer(file) < 0) - return -1; - } - - *buffer = (file->buffer + file->buf_pos); - file->buf_pos += len; - - return 0; -} - -int git_filebuf_printf(git_filebuf *file, const char *format, ...) -{ - va_list arglist; - size_t space_left, len, alloclen; - int written, res; - char *tmp_buffer; - - ENSURE_BUF_OK(file); - - space_left = file->buf_size - file->buf_pos; - - do { - va_start(arglist, format); - written = p_vsnprintf((char *)file->buffer + file->buf_pos, space_left, format, arglist); - va_end(arglist); - - if (written < 0) { - file->last_error = BUFERR_MEM; - return -1; - } - - len = written; - if (len + 1 <= space_left) { - file->buf_pos += len; - return 0; - } - - if (flush_buffer(file) < 0) - return -1; - - space_left = file->buf_size - file->buf_pos; - - } while (len + 1 <= space_left); - - if (GIT_ADD_SIZET_OVERFLOW(&alloclen, len, 1) || - !(tmp_buffer = git__malloc(alloclen))) { - file->last_error = BUFERR_MEM; - return -1; - } - - va_start(arglist, format); - written = p_vsnprintf(tmp_buffer, len + 1, format, arglist); - va_end(arglist); - - if (written < 0) { - git__free(tmp_buffer); - file->last_error = BUFERR_MEM; - return -1; - } - - res = git_filebuf_write(file, tmp_buffer, len); - git__free(tmp_buffer); - - return res; -} - -int git_filebuf_stats(time_t *mtime, size_t *size, git_filebuf *file) -{ - int res; - struct stat st; - - if (file->fd_is_open) - res = p_fstat(file->fd, &st); - else - res = p_stat(file->path_original, &st); - - if (res < 0) { - git_error_set(GIT_ERROR_OS, "could not get stat info for '%s'", - file->path_original); - return res; - } - - if (mtime) - *mtime = st.st_mtime; - if (size) - *size = (size_t)st.st_size; - - return 0; -} |