From c81e80bf35874696d9735f70e5c8327f92b5aca4 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Fri, 16 Jun 2023 01:41:06 +0200 Subject: libsquashfs: merge windows & unix file I/O primitives By adding additional close/duplicate primitives, the remaining, mostly identical istream/ostream/file code is mostly identical between Windows and Unix and be merged, mostly without stitches. Signed-off-by: David Oberhollenzer --- lib/sqfs/src/io/istream.c | 203 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 203 insertions(+) create mode 100644 lib/sqfs/src/io/istream.c (limited to 'lib/sqfs/src/io/istream.c') diff --git a/lib/sqfs/src/io/istream.c b/lib/sqfs/src/io/istream.c new file mode 100644 index 0000000..c3399fe --- /dev/null +++ b/lib/sqfs/src/io/istream.c @@ -0,0 +1,203 @@ +/* SPDX-License-Identifier: LGPL-3.0-or-later */ +/* + * istream.c + * + * Copyright (C) 2019 David Oberhollenzer + */ +#define SQFS_BUILDING_DLL +#include "config.h" + +#include "sqfs/io.h" +#include "sqfs/error.h" +#include "compat.h" + +#include +#include +#include +#include + +#if defined(_WIN32) || defined(__WINDOWS__) +static SSIZE_T read(HANDLE fd, void *ptr, size_t size) +{ + DWORD ret; + + if (!ReadFile(fd, ptr, size, &ret, NULL)) { + os_error_t error = get_os_error_state(); + set_os_error_state(error); + + if (error.w32_errno == ERROR_HANDLE_EOF || + error.w32_errno == ERROR_BROKEN_PIPE) { + return 0; + } + + return -1; + } + + return ret; +} +#endif + +#define BUFSZ (131072) + +typedef struct { + sqfs_istream_t base; + char *path; + sqfs_file_handle_t fd; + + bool eof; + size_t buffer_offset; + size_t buffer_used; + sqfs_u8 buffer[BUFSZ]; +} file_istream_t; + +static int precache(sqfs_istream_t *strm) +{ + file_istream_t *file = (file_istream_t *)strm; + + if (file->eof) + return 0; + + if (file->buffer_offset > 0 && + file->buffer_offset < file->buffer_used) { + memmove(file->buffer, file->buffer + file->buffer_offset, + file->buffer_used - file->buffer_offset); + } + + file->buffer_used -= file->buffer_offset; + file->buffer_offset = 0; + + while (file->buffer_used < BUFSZ) { + ssize_t ret = read(file->fd, file->buffer + file->buffer_used, + BUFSZ - file->buffer_used); + + if (ret == 0) { + file->eof = true; + break; + } + + if (ret < 0) { +#if !defined(_WIN32) && !defined(__WINDOWS__) + if (errno == EINTR) + continue; +#endif + return SQFS_ERROR_IO; + } + + file->buffer_used += ret; + } + + return 0; +} + +static int file_get_buffered_data(sqfs_istream_t *strm, const sqfs_u8 **out, + size_t *size, size_t want) +{ + file_istream_t *file = (file_istream_t *)strm; + + if (want > BUFSZ) + want = BUFSZ; + + if (file->buffer_used == 0 || + (file->buffer_used - file->buffer_offset) < want) { + int ret = precache(strm); + if (ret) + return ret; + } + + *out = file->buffer + file->buffer_offset; + *size = file->buffer_used - file->buffer_offset; + return (file->eof && *size == 0) ? 1 : 0; +} + +static void file_advance_buffer(sqfs_istream_t *strm, size_t count) +{ + file_istream_t *file = (file_istream_t *)strm; + + assert(count <= file->buffer_used); + + file->buffer_offset += count; + + assert(file->buffer_offset <= file->buffer_used); +} + +static const char *file_get_filename(sqfs_istream_t *strm) +{ + return ((file_istream_t *)strm)->path; +} + +static void file_destroy(sqfs_object_t *obj) +{ + file_istream_t *file = (file_istream_t *)obj; + + sqfs_close_native_file(file->fd); + free(file->path); + free(file); +} + +int sqfs_istream_open_handle(sqfs_istream_t **out, const char *path, + sqfs_file_handle_t fd, sqfs_u32 flags) +{ + file_istream_t *file; + sqfs_istream_t *strm; + int ret; + + if (flags & ~(SQFS_FILE_OPEN_ALL_FLAGS)) + return SQFS_ERROR_UNSUPPORTED; + + file = calloc(1, sizeof(*file)); + strm = (sqfs_istream_t *)file; + if (file == NULL) + return SQFS_ERROR_ALLOC; + + sqfs_object_init(file, file_destroy, NULL); + + file->path = strdup(path); + if (file->path == NULL) { + os_error_t err = get_os_error_state(); + free(file); + set_os_error_state(err); + return SQFS_ERROR_ALLOC; + } + + ret = sqfs_duplicate_native_file(fd, &file->fd); + if (ret) { + os_error_t err = get_os_error_state(); + free(file->path); + free(file); + set_os_error_state(err); + return ret; + } + sqfs_close_native_file(fd); + + strm->get_buffered_data = file_get_buffered_data; + strm->advance_buffer = file_advance_buffer; + strm->get_filename = file_get_filename; + + *out = strm; + return 0; +} + +int sqfs_istream_open_file(sqfs_istream_t **out, const char *path, + sqfs_u32 flags) +{ + sqfs_file_handle_t fd; + int ret; + + flags |= SQFS_FILE_OPEN_READ_ONLY; + + if (flags & (SQFS_FILE_OPEN_OVERWRITE | SQFS_FILE_OPEN_NO_SPARSE)) + return SQFS_ERROR_ARG_INVALID; + + ret = sqfs_open_native_file(&fd, path, flags); + if (ret) + return ret; + + ret = sqfs_istream_open_handle(out, path, fd, flags); + if (ret != 0) { + os_error_t err = get_os_error_state(); + sqfs_close_native_file(fd); + set_os_error_state(err); + } + + return ret; +} -- cgit v1.2.3