gstreamer/plugins/elements/gstsparsefile.c
Doug Nazar ab4ec53d56 sparsefile: Fix sparsefile on Win32
When switching between read/write a fseek() or fflush() is required.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/821>
2021-05-14 14:36:57 +01:00

671 lines
14 KiB
C

/* GStreamer
* Copyright (C) 2014 Wim Taymans <wtaymans@redhat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <glib/gstdio.h>
#include "gstsparsefile.h"
#ifdef G_OS_WIN32
#include <io.h> /* lseek, open, close, read */
#undef fseek
#define fseek _fseeki64
#undef off_t
#define off_t guint64
#else
#include <unistd.h>
#endif
#ifdef HAVE_FSEEKO
#define FSEEK_FILE(file,offset) (fseeko (file, (off_t) offset, SEEK_SET) != 0)
#elif defined (G_OS_UNIX)
#define FSEEK_FILE(file,offset) (lseek (fileno (file), (off_t) offset, SEEK_SET) == (off_t) -1)
#else
#define FSEEK_FILE(file,offset) (fseek (file, offset, SEEK_SET) != 0)
#endif
#define GST_SPARSE_FILE_IO_ERROR \
g_quark_from_static_string("gst-sparse-file-io-error-quark")
static GstSparseFileIOErrorEnum
gst_sparse_file_io_error_from_errno (gint err_no);
typedef struct _GstSparseRange GstSparseRange;
struct _GstSparseRange
{
GstSparseRange *next;
gsize start;
gsize stop;
};
#define RANGE_CONTAINS(r,o) ((r)->start <= (o) && (r)->stop > (o))
struct _GstSparseFile
{
gint fd;
FILE *file;
gsize current_pos;
gboolean was_writing;
GstSparseRange *ranges;
guint n_ranges;
GstSparseRange *write_range;
GstSparseRange *read_range;
};
static GstSparseRange *
get_write_range (GstSparseFile * file, gsize offset)
{
GstSparseRange *next, *prev, *result = NULL;
if (file->write_range && file->write_range->stop == offset)
return file->write_range;
prev = NULL;
next = file->ranges;
while (next) {
if (next->start > offset)
break;
if (next->stop >= offset) {
result = next;
break;
}
prev = next;
next = next->next;
}
if (result == NULL) {
result = g_slice_new0 (GstSparseRange);
result->start = offset;
result->stop = offset;
result->next = next;
if (prev)
prev->next = result;
else
file->ranges = result;
file->write_range = result;
file->read_range = NULL;
file->n_ranges++;
}
return result;
}
static GstSparseRange *
get_read_range (GstSparseFile * file, gsize offset, gsize count)
{
GstSparseRange *walk, *result = NULL;
if (file->read_range && RANGE_CONTAINS (file->read_range, offset))
return file->read_range;
for (walk = file->ranges; walk; walk = walk->next) {
if (walk->start > offset)
break;
if (walk->stop >= offset + count) {
result = walk;
break;
}
}
return result;
}
/**
* gst_sparse_file_new:
*
* Make a new #GstSparseFile
*
* Returns: a new #GstSparseFile, gst_sparse_file_free() after usage.
*
* Since: 1.4
*/
GstSparseFile *
gst_sparse_file_new (void)
{
GstSparseFile *result;
result = g_slice_new0 (GstSparseFile);
result->current_pos = 0;
result->ranges = NULL;
result->n_ranges = 0;
return result;
}
/**
* gst_sparse_file_set_fd:
* @file: a #GstSparseFile
* @fd: a file descriptor
*
* Store the data for @file in the file represented with @fd.
*
* Returns: %TRUE when @fd could be set
*
* Since: 1.4
*/
gboolean
gst_sparse_file_set_fd (GstSparseFile * file, gint fd)
{
g_return_val_if_fail (file != NULL, FALSE);
g_return_val_if_fail (fd != 0, FALSE);
file->file = fdopen (fd, "wb+");
file->fd = fd;
return file->file != NULL;
}
/**
* gst_sparse_file_clear:
* @file: a #GstSparseFile
*
* Clear all the ranges in @file.
*/
void
gst_sparse_file_clear (GstSparseFile * file)
{
g_return_if_fail (file != NULL);
g_slice_free_chain (GstSparseRange, file->ranges, next);
file->current_pos = 0;
file->ranges = NULL;
file->n_ranges = 0;
file->was_writing = FALSE;
}
/**
* gst_sparse_file_free:
* @file: a #GstSparseFile
*
* Free the memory used by @file.
*
* Since: 1.4
*/
void
gst_sparse_file_free (GstSparseFile * file)
{
g_return_if_fail (file != NULL);
if (file->file) {
fflush (file->file);
fclose (file->file);
}
g_slice_free_chain (GstSparseRange, file->ranges, next);
g_slice_free (GstSparseFile, file);
}
/**
* gst_sparse_file_write:
* @file: a #GstSparseFile
* @offset: the offset
* @data: the data
* @count: amount of bytes
* @available: amount of bytes already available
* @error: a #GError
*
* Write @count bytes from @data to @file at @offset.
*
* If @available is not %NULL, it will be updated with the amount of
* data already available after the last written byte.
*
* Returns: The number of bytes written or 0 on error.
*
* Since: 1.4
*/
gsize
gst_sparse_file_write (GstSparseFile * file, gsize offset, gconstpointer data,
gsize count, gsize * available, GError ** error)
{
GstSparseRange *range, *next;
gsize stop;
g_return_val_if_fail (file != NULL, 0);
g_return_val_if_fail (count != 0, 0);
if (file->file) {
if (file->current_pos != offset) {
GST_DEBUG ("seeking to %" G_GSIZE_FORMAT, offset);
if (FSEEK_FILE (file->file, offset))
goto error;
} else if (!file->was_writing) {
fflush (file->file);
}
file->was_writing = TRUE;
if (fwrite (data, count, 1, file->file) != 1)
goto error;
}
file->current_pos = offset + count;
/* update the new stop position in the range */
range = get_write_range (file, offset);
stop = offset + count;
range->stop = MAX (range->stop, stop);
/* see if we can merge with next region */
while ((next = range->next)) {
if (next->start > range->stop)
break;
GST_DEBUG ("merging range %" G_GSIZE_FORMAT "-%" G_GSIZE_FORMAT ", next %"
G_GSIZE_FORMAT "-%" G_GSIZE_FORMAT, range->start, range->stop,
next->start, next->stop);
range->stop = MAX (next->stop, range->stop);
range->next = next->next;
if (file->write_range == next)
file->write_range = NULL;
if (file->read_range == next)
file->read_range = NULL;
g_slice_free (GstSparseRange, next);
file->n_ranges--;
}
if (available)
*available = range->stop - stop;
return count;
/* ERRORS */
error:
{
g_set_error (error, GST_SPARSE_FILE_IO_ERROR,
gst_sparse_file_io_error_from_errno (errno), "Error writing file: %s",
g_strerror (errno));
return 0;
}
}
/**
* gst_sparse_file_read:
* @file: a #GstSparseFile
* @offset: the offset
* @data: the data
* @count: amount of bytes
* @remaining: amount of bytes remaining
* @error: a #GError
*
* Read @count bytes from @file at @offset into @data.
*
* On error, @error will be set. If there are no @count bytes available
* at @offset, %GST_SPARSE_FILE_IO_ERROR_WOULD_BLOCK is returned.
*
* @remaining will be set to the amount of bytes remaining in the read
* range.
*
* Returns: The number of bytes read of 0 on error.
*
* Since: 1.4
*/
gsize
gst_sparse_file_read (GstSparseFile * file, gsize offset, gpointer data,
gsize count, gsize * remaining, GError ** error)
{
GstSparseRange *range;
gsize res = 0;
g_return_val_if_fail (file != NULL, 0);
g_return_val_if_fail (count != 0, 0);
if ((range = get_read_range (file, offset, count)) == NULL)
goto no_range;
if (file->file) {
if (file->current_pos != offset) {
GST_DEBUG ("seeking from %" G_GSIZE_FORMAT " to %" G_GSIZE_FORMAT,
file->current_pos, offset);
if (FSEEK_FILE (file->file, offset))
goto error;
} else if (file->was_writing) {
fflush (file->file);
}
file->was_writing = FALSE;
res = fread (data, 1, count, file->file);
if (G_UNLIKELY (res < count))
goto error;
}
file->current_pos = offset + res;
if (remaining)
*remaining = range->stop - file->current_pos;
return count;
/* ERRORS */
no_range:
{
g_set_error_literal (error, GST_SPARSE_FILE_IO_ERROR,
GST_SPARSE_FILE_IO_ERROR_WOULD_BLOCK, "Offset not written to file yet");
return 0;
}
error:
{
if (ferror (file->file)) {
g_set_error (error, GST_SPARSE_FILE_IO_ERROR,
gst_sparse_file_io_error_from_errno (errno), "Error reading file: %s",
g_strerror (errno));
} else if (feof (file->file)) {
return res;
}
return 0;
}
}
/**
* gst_sparse_file_n_ranges:
* @file: a #GstSparseFile
*
* Get the number of ranges that are written in @file.
*
* Returns: the number of written ranges.
*
* Since: 1.4
*/
guint
gst_sparse_file_n_ranges (GstSparseFile * file)
{
g_return_val_if_fail (file != NULL, 0);
return file->n_ranges;
}
/**
* gst_sparse_file_get_range_before:
* @file: a #GstSparseFile
* @offset: the range offset
* @start: result start
* @stop: result stop
*
* Get the start and stop offset of the range containing data before or
* including @offset.
*
* Returns: %TRUE if the range with data before @offset exists.
*
* Since: 1.4
*/
gboolean
gst_sparse_file_get_range_before (GstSparseFile * file, gsize offset,
gsize * start, gsize * stop)
{
GstSparseRange *walk, *result = NULL;
g_return_val_if_fail (file != NULL, FALSE);
for (walk = file->ranges; walk; walk = walk->next) {
GST_DEBUG ("start %" G_GSIZE_FORMAT " > %" G_GSIZE_FORMAT,
walk->stop, offset);
if (walk->start > offset)
break;
if (walk->start <= offset)
result = walk;
}
if (result) {
if (start)
*start = result->start;
if (stop)
*stop = result->stop;
}
return result != NULL;
}
/**
* gst_sparse_file_get_range_after:
* @file: a #GstSparseFile
* @offset: the range offset
* @start: result start
* @stop: result stop
*
* Get the start and stop offset of the range containing data after or
* including @offset.
*
* Returns: %TRUE if the range with data after @offset exists.
*
* Since: 1.4
*/
gboolean
gst_sparse_file_get_range_after (GstSparseFile * file, gsize offset,
gsize * start, gsize * stop)
{
GstSparseRange *walk, *result = NULL;
g_return_val_if_fail (file != NULL, FALSE);
for (walk = file->ranges; walk; walk = walk->next) {
GST_DEBUG ("stop %" G_GSIZE_FORMAT " > %" G_GSIZE_FORMAT,
walk->stop, offset);
if (walk->stop > offset) {
result = walk;
break;
}
}
if (result) {
if (start)
*start = result->start;
if (stop)
*stop = result->stop;
}
return result != NULL;
}
/* we don't want to rely on libgio just for g_io_error_from_errno() */
static GstSparseFileIOErrorEnum
gst_sparse_file_io_error_from_errno (gint err_no)
{
switch (err_no) {
#ifdef EEXIST
case EEXIST:
return GST_SPARSE_FILE_IO_ERROR_EXISTS;
break;
#endif
#ifdef EISDIR
case EISDIR:
return GST_SPARSE_FILE_IO_ERROR_IS_DIRECTORY;
break;
#endif
#ifdef EACCES
case EACCES:
return GST_SPARSE_FILE_IO_ERROR_PERMISSION_DENIED;
break;
#endif
#ifdef ENAMETOOLONG
case ENAMETOOLONG:
return GST_SPARSE_FILE_IO_ERROR_FILENAME_TOO_LONG;
break;
#endif
#ifdef ENOENT
case ENOENT:
return GST_SPARSE_FILE_IO_ERROR_NOT_FOUND;
break;
#endif
#ifdef ENOTDIR
case ENOTDIR:
return GST_SPARSE_FILE_IO_ERROR_NOT_DIRECTORY;
break;
#endif
#ifdef EROFS
case EROFS:
return GST_SPARSE_FILE_IO_ERROR_READ_ONLY;
break;
#endif
#ifdef ELOOP
case ELOOP:
return GST_SPARSE_FILE_IO_ERROR_TOO_MANY_LINKS;
break;
#endif
#ifdef ENOSPC
case ENOSPC:
return GST_SPARSE_FILE_IO_ERROR_NO_SPACE;
break;
#endif
#ifdef ENOMEM
case ENOMEM:
return GST_SPARSE_FILE_IO_ERROR_NO_SPACE;
break;
#endif
#ifdef EINVAL
case EINVAL:
return GST_SPARSE_FILE_IO_ERROR_INVALID_ARGUMENT;
break;
#endif
#ifdef EPERM
case EPERM:
return GST_SPARSE_FILE_IO_ERROR_PERMISSION_DENIED;
break;
#endif
#ifdef ECANCELED
case ECANCELED:
return GST_SPARSE_FILE_IO_ERROR_CANCELLED;
break;
#endif
/* ENOTEMPTY == EEXIST on AIX for backward compatibility reasons */
#if defined (ENOTEMPTY) && (!defined (EEXIST) || (ENOTEMPTY != EEXIST))
case ENOTEMPTY:
return GST_SPARSE_FILE_IO_ERROR_NOT_EMPTY;
break;
#endif
#ifdef ENOTSUP
case ENOTSUP:
return GST_SPARSE_FILE_IO_ERROR_NOT_SUPPORTED;
break;
#endif
/* EOPNOTSUPP == ENOTSUP on Linux, but POSIX considers them distinct */
#if defined (EOPNOTSUPP) && (!defined (ENOTSUP) || (EOPNOTSUPP != ENOTSUP))
case EOPNOTSUPP:
return GST_SPARSE_FILE_IO_ERROR_NOT_SUPPORTED;
break;
#endif
#ifdef EPROTONOSUPPORT
case EPROTONOSUPPORT:
return GST_SPARSE_FILE_IO_ERROR_NOT_SUPPORTED;
break;
#endif
#ifdef ESOCKTNOSUPPORT
case ESOCKTNOSUPPORT:
return GST_SPARSE_FILE_IO_ERROR_NOT_SUPPORTED;
break;
#endif
#ifdef EPFNOSUPPORT
case EPFNOSUPPORT:
return GST_SPARSE_FILE_IO_ERROR_NOT_SUPPORTED;
break;
#endif
#ifdef EAFNOSUPPORT
case EAFNOSUPPORT:
return GST_SPARSE_FILE_IO_ERROR_NOT_SUPPORTED;
break;
#endif
#ifdef ETIMEDOUT
case ETIMEDOUT:
return GST_SPARSE_FILE_IO_ERROR_TIMED_OUT;
break;
#endif
#ifdef EBUSY
case EBUSY:
return GST_SPARSE_FILE_IO_ERROR_BUSY;
break;
#endif
#ifdef EWOULDBLOCK
case EWOULDBLOCK:
return GST_SPARSE_FILE_IO_ERROR_WOULD_BLOCK;
break;
#endif
/* EWOULDBLOCK == EAGAIN on most systems, but POSIX considers them distinct */
#if defined (EAGAIN) && (!defined (EWOULDBLOCK) || (EWOULDBLOCK != EAGAIN))
case EAGAIN:
return GST_SPARSE_FILE_IO_ERROR_WOULD_BLOCK;
break;
#endif
#ifdef EMFILE
case EMFILE:
return GST_SPARSE_FILE_IO_ERROR_TOO_MANY_OPEN_FILES;
break;
#endif
#ifdef EADDRINUSE
case EADDRINUSE:
return GST_SPARSE_FILE_IO_ERROR_ADDRESS_IN_USE;
break;
#endif
#ifdef EHOSTUNREACH
case EHOSTUNREACH:
return GST_SPARSE_FILE_IO_ERROR_HOST_UNREACHABLE;
break;
#endif
#ifdef ENETUNREACH
case ENETUNREACH:
return GST_SPARSE_FILE_IO_ERROR_NETWORK_UNREACHABLE;
break;
#endif
#ifdef ECONNREFUSED
case ECONNREFUSED:
return GST_SPARSE_FILE_IO_ERROR_CONNECTION_REFUSED;
break;
#endif
#ifdef EPIPE
case EPIPE:
return GST_SPARSE_FILE_IO_ERROR_BROKEN_PIPE;
break;
#endif
default:
return GST_SPARSE_FILE_IO_ERROR_FAILED;
break;
}
}