/*

  * buffered file I/O

  * Copyright (c) 2001 Fabrice Bellard

  *

  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

  * version 2.1 of the License, or (at your option) any later version.

  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.

  *

  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */

 
 #include "libavutil/avstring.h"

 #include "libavutil/internal.h"

 #include "libavutil/opt.h"

 #include "avformat.h"

 #if HAVE_DIRENT_H

 #include <dirent.h>

 #endif

 #include <fcntl.h>

 #if HAVE_IO_H

 #include <io.h>
 #endif

 #if HAVE_UNISTD_H

 #include <unistd.h>

 #endif

 #include <sys/stat.h>

 #include <stdlib.h>

 #include "os_support.h"

 #include "url.h"

 /* Some systems may not have S_ISFIFO */
 #ifndef S_ISFIFO
 #  ifdef S_IFIFO
 #    define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
 #  else
 #    define S_ISFIFO(m) 0
 #  endif
 #endif

 /* Not available in POSIX.1-1996 */
 #ifndef S_ISLNK
 #  ifdef S_IFLNK
 #    define S_ISLNK(m) (((m) & S_IFLNK) == S_IFLNK)
 #  else
 #    define S_ISLNK(m) 0
 #  endif
 #endif
 
 /* Not available in POSIX.1-1996 */
 #ifndef S_ISSOCK
 #  ifdef S_IFSOCK
 #    define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
 #  else
 #    define S_ISSOCK(m) 0
 #  endif
 #endif
 

 /* standard file protocol */
 

 typedef struct FileContext {

     const AVClass *class;

     int fd;

     int trunc;

     int blocksize;

     int follow;

 #if HAVE_DIRENT_H

     DIR *dir;

 #endif

 } FileContext;
 

 static const AVOption file_options[] = {

     { "truncate", "truncate existing files on write", offsetof(FileContext, trunc), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },

     { "blocksize", "set I/O operation maximum block size", offsetof(FileContext, blocksize), AV_OPT_TYPE_INT, { .i64 = INT_MAX }, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },

     { "follow", "Follow a file as it is being written", offsetof(FileContext, follow), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AV_OPT_FLAG_DECODING_PARAM },

     { NULL }
 };
 
 static const AVOption pipe_options[] = {
     { "blocksize", "set I/O operation maximum block size", offsetof(FileContext, blocksize), AV_OPT_TYPE_INT, { .i64 = INT_MAX }, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },

     { NULL }
 };
 
 static const AVClass file_class = {
     .class_name = "file",
     .item_name  = av_default_item_name,
     .option     = file_options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 static const AVClass pipe_class = {
     .class_name = "pipe",
     .item_name  = av_default_item_name,
     .option     = pipe_options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 static int file_read(URLContext *h, unsigned char *buf, int size)
 {

     FileContext *c = h->priv_data;

     int ret;

     size = FFMIN(size, c->blocksize);

     ret = read(c->fd, buf, size);

     if (ret == 0 && c->follow)
         return AVERROR(EAGAIN);

     if (ret == 0)
         return AVERROR_EOF;

     return (ret == -1) ? AVERROR(errno) : ret;

 }
 
 static int file_write(URLContext *h, const unsigned char *buf, int size)
 {

     FileContext *c = h->priv_data;

     int ret;

     size = FFMIN(size, c->blocksize);

     ret = write(c->fd, buf, size);

     return (ret == -1) ? AVERROR(errno) : ret;

 }
 
 static int file_get_handle(URLContext *h)
 {

     FileContext *c = h->priv_data;
     return c->fd;

 }
 

 static int file_check(URLContext *h, int mask)
 {

     int ret = 0;

     const char *filename = h->filename;
     av_strstart(filename, "file:", &filename);
 
     {
 #if HAVE_ACCESS && defined(R_OK)
     if (access(filename, F_OK) < 0)

         return AVERROR(errno);

     if (mask&AVIO_FLAG_READ)

         if (access(filename, R_OK) >= 0)

             ret |= AVIO_FLAG_READ;
     if (mask&AVIO_FLAG_WRITE)

         if (access(filename, W_OK) >= 0)

             ret |= AVIO_FLAG_WRITE;

 #else
     struct stat st;

 #   ifndef _WIN32

     ret = stat(filename, &st);

 #   else
     ret = win32_stat(filename, &st);
 #   endif

     if (ret < 0)
         return AVERROR(errno);
 
     ret |= st.st_mode&S_IRUSR ? mask&AVIO_FLAG_READ  : 0;
     ret |= st.st_mode&S_IWUSR ? mask&AVIO_FLAG_WRITE : 0;
 #endif

     }

     return ret;
 }
 

 static int file_delete(URLContext *h)
 {
 #if HAVE_UNISTD_H
     int ret;
     const char *filename = h->filename;
     av_strstart(filename, "file:", &filename);
 
     ret = rmdir(filename);
     if (ret < 0 && errno == ENOTDIR)
         ret = unlink(filename);
     if (ret < 0)
         return AVERROR(errno);
 
     return ret;
 #else
     return AVERROR(ENOSYS);
 #endif /* HAVE_UNISTD_H */
 }
 
 static int file_move(URLContext *h_src, URLContext *h_dst)
 {
     const char *filename_src = h_src->filename;
     const char *filename_dst = h_dst->filename;
     av_strstart(filename_src, "file:", &filename_src);

     av_strstart(filename_dst, "file:", &filename_dst);

 
     if (rename(filename_src, filename_dst) < 0)
         return AVERROR(errno);
 
     return 0;
 }
 

 #if CONFIG_FILE_PROTOCOL
 

 static int file_open(URLContext *h, const char *filename, int flags)
 {

     FileContext *c = h->priv_data;

     int access;
     int fd;

     struct stat st;

     av_strstart(filename, "file:", &filename);

     if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ) {

         access = O_CREAT | O_RDWR;
         if (c->trunc)
             access |= O_TRUNC;

     } else if (flags & AVIO_FLAG_WRITE) {

         access = O_CREAT | O_WRONLY;
         if (c->trunc)
             access |= O_TRUNC;

     } else {
         access = O_RDONLY;
     }

 #ifdef O_BINARY

     access |= O_BINARY;
 #endif

     fd = avpriv_open(filename, access, 0666);

     if (fd == -1)

         return AVERROR(errno);

     c->fd = fd;

     h->is_streamed = !fstat(fd, &st) && S_ISFIFO(st.st_mode);

     /* Buffer writes more than the default 32k to improve throughput especially
      * with networked file systems */
     if (!h->is_streamed && flags & AVIO_FLAG_WRITE)
         h->min_packet_size = h->max_packet_size = 262144;
 

     return 0;
 }
 
 /* XXX: use llseek */

 static int64_t file_seek(URLContext *h, int64_t pos, int whence)

 {

     FileContext *c = h->priv_data;

     int64_t ret;

     if (whence == AVSEEK_SIZE) {
         struct stat st;

         ret = fstat(c->fd, &st);

         return ret < 0 ? AVERROR(errno) : (S_ISFIFO(st.st_mode) ? 0 : st.st_size);

     }

 
     ret = lseek(c->fd, pos, whence);
 
     return ret < 0 ? AVERROR(errno) : ret;

 }
 
 static int file_close(URLContext *h)
 {

     FileContext *c = h->priv_data;
     return close(c->fd);

 }
 

 static int file_open_dir(URLContext *h)
 {

 #if HAVE_LSTAT

     FileContext *c = h->priv_data;
 
     c->dir = opendir(h->filename);
     if (!c->dir)
         return AVERROR(errno);
 
     return 0;

 #else
     return AVERROR(ENOSYS);

 #endif /* HAVE_LSTAT */

 }
 
 static int file_read_dir(URLContext *h, AVIODirEntry **next)
 {

 #if HAVE_LSTAT

     FileContext *c = h->priv_data;
     struct dirent *dir;
     char *fullpath = NULL;
 
     *next = ff_alloc_dir_entry();
     if (!*next)
         return AVERROR(ENOMEM);
     do {
         errno = 0;
         dir = readdir(c->dir);
         if (!dir) {
             av_freep(next);
             return AVERROR(errno);
         }
     } while (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."));
 
     fullpath = av_append_path_component(h->filename, dir->d_name);
     if (fullpath) {
         struct stat st;

         if (!lstat(fullpath, &st)) {
             if (S_ISDIR(st.st_mode))
                 (*next)->type = AVIO_ENTRY_DIRECTORY;
             else if (S_ISFIFO(st.st_mode))
                 (*next)->type = AVIO_ENTRY_NAMED_PIPE;
             else if (S_ISCHR(st.st_mode))
                 (*next)->type = AVIO_ENTRY_CHARACTER_DEVICE;
             else if (S_ISBLK(st.st_mode))
                 (*next)->type = AVIO_ENTRY_BLOCK_DEVICE;
             else if (S_ISLNK(st.st_mode))
                 (*next)->type = AVIO_ENTRY_SYMBOLIC_LINK;
             else if (S_ISSOCK(st.st_mode))
                 (*next)->type = AVIO_ENTRY_SOCKET;
             else if (S_ISREG(st.st_mode))
                 (*next)->type = AVIO_ENTRY_FILE;
             else
                 (*next)->type = AVIO_ENTRY_UNKNOWN;
 

             (*next)->group_id = st.st_gid;
             (*next)->user_id = st.st_uid;
             (*next)->size = st.st_size;
             (*next)->filemode = st.st_mode & 0777;
             (*next)->modification_timestamp = INT64_C(1000000) * st.st_mtime;
             (*next)->access_timestamp =  INT64_C(1000000) * st.st_atime;
             (*next)->status_change_timestamp = INT64_C(1000000) * st.st_ctime;
         }
         av_free(fullpath);
     }
 
     (*next)->name = av_strdup(dir->d_name);
     return 0;

 #else
     return AVERROR(ENOSYS);

 #endif /* HAVE_LSTAT */

 }
 
 static int file_close_dir(URLContext *h)
 {

 #if HAVE_LSTAT

     FileContext *c = h->priv_data;
     closedir(c->dir);
     return 0;

 #else
     return AVERROR(ENOSYS);

 #endif /* HAVE_LSTAT */

 }
 

 const URLProtocol ff_file_protocol = {

     .name                = "file",
     .url_open            = file_open,
     .url_read            = file_read,
     .url_write           = file_write,
     .url_seek            = file_seek,
     .url_close           = file_close,

     .url_get_file_handle = file_get_handle,

     .url_check           = file_check,

     .url_delete          = file_delete,
     .url_move            = file_move,

     .priv_data_size      = sizeof(FileContext),

     .priv_data_class     = &file_class,

     .url_open_dir        = file_open_dir,
     .url_read_dir        = file_read_dir,
     .url_close_dir       = file_close_dir,

     .default_whitelist   = "file,crypto"

 };
 

 #endif /* CONFIG_FILE_PROTOCOL */
 
 #if CONFIG_PIPE_PROTOCOL

 
 static int pipe_open(URLContext *h, const char *filename, int flags)
 {

     FileContext *c = h->priv_data;

     int fd;

     char *final;

     av_strstart(filename, "pipe:", &filename);

     fd = strtol(filename, &final, 10);
     if((filename == final) || *final ) {/* No digits found, or something like 10ab */

         if (flags & AVIO_FLAG_WRITE) {

             fd = 1;
         } else {
             fd = 0;
         }

     }

 #if HAVE_SETMODE

     setmode(fd, O_BINARY);
 #endif

     c->fd = fd;

     h->is_streamed = 1;

     return 0;
 }
 

 const URLProtocol ff_pipe_protocol = {

     .name                = "pipe",
     .url_open            = pipe_open,
     .url_read            = file_read,
     .url_write           = file_write,

     .url_get_file_handle = file_get_handle,

     .url_check           = file_check,

     .priv_data_size      = sizeof(FileContext),

     .priv_data_class     = &pipe_class,

     .default_whitelist   = "crypto"

 };

 
 #endif /* CONFIG_PIPE_PROTOCOL */