From 1e255d0f6c472bb3c710aea1ea8dc5d27c0fba4a Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Fri, 4 Sep 2020 18:26:16 +0200 Subject: Add stream I/O abstraction library Signed-off-by: David Oberhollenzer --- lib/fstream/unix/istream.c | 124 ++++++++++++++++++++++++++++++++++++ lib/fstream/unix/ostream.c | 152 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 276 insertions(+) create mode 100644 lib/fstream/unix/istream.c create mode 100644 lib/fstream/unix/ostream.c (limited to 'lib/fstream/unix') diff --git a/lib/fstream/unix/istream.c b/lib/fstream/unix/istream.c new file mode 100644 index 0000000..5898141 --- /dev/null +++ b/lib/fstream/unix/istream.c @@ -0,0 +1,124 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * istream.c + * + * Copyright (C) 2019 David Oberhollenzer + */ +#include "../internal.h" + +typedef struct { + istream_t base; + char *path; + int fd; + bool eof; + + sqfs_u8 buffer[BUFSZ]; +} file_istream_t; + +static int file_precache(istream_t *strm) +{ + file_istream_t *file = (file_istream_t *)strm; + ssize_t ret; + size_t diff; + + while (strm->buffer_used < sizeof(file->buffer)) { + diff = sizeof(file->buffer) - strm->buffer_used; + + ret = read(file->fd, strm->buffer + strm->buffer_used, diff); + + if (ret == 0) { + file->eof = true; + break; + } + + if (ret < 0) { + if (errno == EINTR) + continue; + + perror(file->path); + return -1; + } + + strm->buffer_used += ret; + } + + return 0; +} + +static const char *file_get_filename(istream_t *strm) +{ + file_istream_t *file = (file_istream_t *)strm; + + return file->path; +} + +static void file_destroy(sqfs_object_t *obj) +{ + file_istream_t *file = (file_istream_t *)obj; + + if (file->fd != STDIN_FILENO) + close(file->fd); + + free(file->path); + free(file); +} + +istream_t *istream_open_file(const char *path) +{ + file_istream_t *file = calloc(1, sizeof(*file)); + sqfs_object_t *obj = (sqfs_object_t *)file; + istream_t *strm = (istream_t *)file; + + if (file == NULL) { + perror(path); + return NULL; + } + + file->path = strdup(path); + if (file->path == NULL) { + perror(path); + goto fail_free; + } + + file->fd = open(path, O_RDONLY); + if (file->fd < 0) { + perror(path); + goto fail_path; + } + + strm->buffer = file->buffer; + strm->precache = file_precache; + strm->get_filename = file_get_filename; + obj->destroy = file_destroy; + return strm; +fail_path: + free(file->path); +fail_free: + free(file); + return NULL; +} + +istream_t *istream_open_stdin(void) +{ + file_istream_t *file = calloc(1, sizeof(*file)); + sqfs_object_t *obj = (sqfs_object_t *)file; + istream_t *strm = (istream_t *)file; + + if (file == NULL) + goto fail; + + file->path = strdup("stdin"); + if (file->path == NULL) + goto fail; + + file->fd = STDIN_FILENO; + strm->buffer = file->buffer; + strm->precache = file_precache; + strm->get_filename = file_get_filename; + obj->destroy = file_destroy; + return strm; +fail: + perror("creating file wrapper for stdin"); + free(file); + return NULL; +} diff --git a/lib/fstream/unix/ostream.c b/lib/fstream/unix/ostream.c new file mode 100644 index 0000000..dac675f --- /dev/null +++ b/lib/fstream/unix/ostream.c @@ -0,0 +1,152 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * ostream.c + * + * Copyright (C) 2019 David Oberhollenzer + */ +#include "../internal.h" + +typedef struct { + ostream_t base; + char *path; + int fd; +} file_ostream_t; + +static int file_append(ostream_t *strm, const void *data, size_t size) +{ + file_ostream_t *file = (file_ostream_t *)strm; + ssize_t ret; + + while (size > 0) { + ret = write(file->fd, data, size); + + if (ret == 0) { + fprintf(stderr, "%s: truncated data write.\n", + file->path); + return -1; + } + + if (ret < 0) { + if (errno == EINTR) + continue; + + perror(file->path); + return -1; + } + + size -= ret; + data = (const char *)data + ret; + } + + return 0; +} + +static int file_append_sparse(ostream_t *strm, size_t size) +{ + file_ostream_t *file = (file_ostream_t *)strm; + + if (lseek(file->fd, size, SEEK_CUR) == (off_t)-1) { + perror(file->path); + return -1; + } + + return 0; +} + +static int file_flush(ostream_t *strm) +{ + file_ostream_t *file = (file_ostream_t *)strm; + + if (fsync(file->fd) != 0) { + perror(file->path); + return -1; + } + + return 0; +} + +static void file_destroy(sqfs_object_t *obj) +{ + file_ostream_t *file = (file_ostream_t *)obj; + + if (file->fd != STDOUT_FILENO) + close(file->fd); + + free(file->path); + free(file); +} + +static const char *file_get_filename(ostream_t *strm) +{ + file_ostream_t *file = (file_ostream_t *)strm; + + return file->path; +} + +ostream_t *ostream_open_file(const char *path, int flags) +{ + file_ostream_t *file = calloc(1, sizeof(*file)); + sqfs_object_t *obj = (sqfs_object_t *)file; + ostream_t *strm = (ostream_t *)file; + + if (file == NULL) { + perror(path); + return NULL; + } + + file->path = strdup(path); + if (file->path == NULL) { + perror(path); + goto fail_free; + } + + if (flags & OSTREAM_OPEN_OVERWRITE) { + file->fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644); + } else { + file->fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0644); + } + + if (file->fd < 0) { + perror(path); + goto fail_path; + } + + if (flags & OSTREAM_OPEN_SPARSE) + strm->append_sparse = file_append_sparse; + + strm->append = file_append; + strm->flush = file_flush; + strm->get_filename = file_get_filename; + obj->destroy = file_destroy; + return strm; +fail_path: + free(file->path); +fail_free: + free(file); + return NULL; +} + +ostream_t *ostream_open_stdout(void) +{ + file_ostream_t *file = calloc(1, sizeof(*file)); + sqfs_object_t *obj = (sqfs_object_t *)file; + ostream_t *strm = (ostream_t *)file; + + if (file == NULL) + goto fail; + + file->path = strdup("stdout"); + if (file->path == NULL) + goto fail; + + file->fd = STDOUT_FILENO; + strm->append = file_append; + strm->flush = file_flush; + strm->get_filename = file_get_filename; + obj->destroy = file_destroy; + return strm; +fail: + perror("creating file wrapper for stdout"); + free(file); + return NULL; +} -- cgit v1.2.3