Commit 2ec9d996 authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont
Browse files

block_File: loads a file into a block_t

parent c65b4ea9
......@@ -148,17 +148,8 @@ static inline void block_Release( block_t *p_block )
p_block->pf_release( p_block );
}
/**
* Creates a block from a virtual address memory mapping (mmap).
* This is provided by LibVLC so that mmap blocks can safely be deallocated
* even after the allocating plugin has been unloaded from memory.
*
* @param addr base address of the mapping (as returned by mmap)
* @param length length (bytes) of the mapping (as passed to mmap)
* @return NULL if addr is MAP_FAILED, or an error occurred (in the later
* case, munmap(addr, length) is invoked before returning).
*/
VLC_EXPORT( block_t *, block_mmap_Alloc, (void *addr, size_t length) );
VLC_EXPORT( block_t *, block_File, (int fd) );
/****************************************************************************
* Chains of blocks functions helper
......
......@@ -41,6 +41,7 @@ block_FifoRelease
block_FifoShow
block_FifoSize
block_FifoWake
block_File
block_Init
block_mmap_Alloc
block_Realloc
......
......@@ -29,6 +29,7 @@
#endif
#include <vlc/vlc.h>
#include <sys/stat.h>
#include "vlc_block.h"
/*****************************************************************************
......@@ -208,6 +209,16 @@ static void block_mmap_Release (block_t *block)
free (p_sys);
}
/**
* Creates a block from a virtual address memory mapping (mmap).
* This is provided by LibVLC so that mmap blocks can safely be deallocated
* even after the allocating plugin has been unloaded from memory.
*
* @param addr base address of the mapping (as returned by mmap)
* @param length length (bytes) of the mapping (as passed to mmap)
* @return NULL if addr is MAP_FAILED, or an error occurred (in the later
* case, munmap(addr, length) is invoked before returning).
*/
block_t *block_mmap_Alloc (void *addr, size_t length)
{
if (addr == MAP_FAILED)
......@@ -247,6 +258,79 @@ ssize_t pread (int fd, void *buf, size_t count, off_t offset)
}
#endif
/**
* Loads a file into a block of memory. If possible a private file mapping is
* created. Otherwise, the file is read normally. On 32-bits platforms, this
* function will not work for very large files, due to memory space
* constraints.
*
* @param fd file descriptor to load from
* @return a new block with the file content at p_buffer, and file length at
* i_buffer (release it with block_Release()), or NULL upon error (see errno).
*/
block_t *block_File (int fd)
{
size_t length;
struct stat st;
/* First, get the file size */
if (fstat (fd, &st))
return NULL;
/* st_size is meaningful for regular files, shared memory and typed memory.
* It's also meaning for symlinks, but that's not possible with fstat().
* In other cases, it's undefined, and we should really not go further. */
#ifndef S_TYPEISSHM
# define S_TYPEISSHM( buf ) (0)
#endif
if (S_ISDIR (st.st_mode))
{
errno = EISDIR;
return NULL;
}
if (!S_ISREG (st.st_mode) && !S_TYPEISSHM (&st))
{
errno = ESPIPE;
return NULL;
}
/* Prevent an integer overflow in mmap() and malloc() */
if (st.st_size >= SIZE_MAX)
{
errno = ENOMEM;
return NULL;
}
length = (size_t)st.st_size;
#ifdef HAVE_MMAP
if (length > 0)
{
void *addr;
addr = mmap (NULL, length, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
if (addr != MAP_FAILED)
return block_mmap_Alloc (addr, length);
}
#endif
/* If mmap() is not implemented by the OS _or_ the filesystem... */
block_t *block = block_Alloc (length);
if (block == NULL)
return NULL;
for (size_t i = 0; i < length;)
{
ssize_t len = pread (fd, block->p_buffer + i, length - i, i);
if (len == -1)
{
block_Release (block);
return NULL;
}
i += len;
}
return block;
}
/*****************************************************************************
* block_fifo_t management
*****************************************************************************/
......
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