VFS: More VFile memory interfaces

This commit is contained in:
Jeffrey Pfau 2016-01-02 17:07:44 -08:00
parent d662ba98de
commit 6f62852671
2 changed files with 150 additions and 0 deletions
src/util

View File

@ -67,6 +67,8 @@ struct VFile* VFileOpenFD(const char* path, int flags);
struct VFile* VFileFOpen(const char* path, const char* mode);
struct VFile* VFileFromFD(int fd);
struct VFile* VFileFromMemory(void* mem, size_t size);
struct VFile* VFileFromConstMemory(const void* mem, size_t size);
struct VFile* VFileMemChunk(const void* mem, size_t size);
struct VFile* VFileFromFILE(FILE* file);
struct VDir* VDirOpen(const char* path);

View File

@ -4,6 +4,7 @@
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "util/vfs.h"
#include "util/memory.h"
struct VFileMem {
struct VFile d;
@ -13,12 +14,17 @@ struct VFileMem {
};
static bool _vfmClose(struct VFile* vf);
static bool _vfmCloseFree(struct VFile* vf);
static off_t _vfmSeek(struct VFile* vf, off_t offset, int whence);
static off_t _vfmSeekExpanding(struct VFile* vf, off_t offset, int whence);
static ssize_t _vfmRead(struct VFile* vf, void* buffer, size_t size);
static ssize_t _vfmWrite(struct VFile* vf, const void* buffer, size_t size);
static ssize_t _vfmWriteExpanding(struct VFile* vf, const void* buffer, size_t size);
static ssize_t _vfmWriteNoop(struct VFile* vf, const void* buffer, size_t size);
static void* _vfmMap(struct VFile* vf, size_t size, int flags);
static void _vfmUnmap(struct VFile* vf, void* memory, size_t size);
static void _vfmTruncate(struct VFile* vf, size_t size);
static void _vfmTruncateNoop(struct VFile* vf, size_t size);
static ssize_t _vfmSize(struct VFile* vf);
static bool _vfmSync(struct VFile* vf, const void* buffer, size_t size);
@ -42,6 +48,63 @@ struct VFile* VFileFromMemory(void* mem, size_t size) {
vfm->d.write = _vfmWrite;
vfm->d.map = _vfmMap;
vfm->d.unmap = _vfmUnmap;
vfm->d.truncate = _vfmTruncateNoop;
vfm->d.size = _vfmSize;
vfm->d.sync = _vfmSync;
return &vfm->d;
}
struct VFile* VFileFromConstMemory(const void* mem, size_t size) {
if (!mem || !size) {
return 0;
}
struct VFileMem* vfm = malloc(sizeof(struct VFileMem));
if (!vfm) {
return 0;
}
vfm->mem = (void*) mem;
vfm->size = size;
vfm->offset = 0;
vfm->d.close = _vfmClose;
vfm->d.seek = _vfmSeek;
vfm->d.read = _vfmRead;
vfm->d.readline = VFileReadline;
vfm->d.write = _vfmWriteNoop;
vfm->d.map = _vfmMap;
vfm->d.unmap = _vfmUnmap;
vfm->d.truncate = _vfmTruncateNoop;
vfm->d.size = _vfmSize;
vfm->d.sync = _vfmSync;
return &vfm->d;
}
struct VFile* VFileMemChunk(const void* mem, size_t size) {
struct VFileMem* vfm = malloc(sizeof(struct VFileMem));
if (!vfm) {
return 0;
}
vfm->size = size;
if (size) {
vfm->mem = anonymousMemoryMap(size);
if (mem) {
memcpy(vfm->mem, mem, size);
}
} else {
vfm->mem = 0;
}
vfm->offset = 0;
vfm->d.close = _vfmCloseFree;
vfm->d.seek = _vfmSeekExpanding;
vfm->d.read = _vfmRead;
vfm->d.readline = VFileReadline;
vfm->d.write = _vfmWriteExpanding;
vfm->d.map = _vfmMap;
vfm->d.unmap = _vfmUnmap;
vfm->d.truncate = _vfmTruncate;
vfm->d.size = _vfmSize;
vfm->d.sync = _vfmSync;
@ -49,6 +112,16 @@ struct VFile* VFileFromMemory(void* mem, size_t size) {
return &vfm->d;
}
void _vfmExpand(struct VFileMem* vfm, size_t newSize) {
void* oldBuf = vfm->mem;
vfm->mem = anonymousMemoryMap(newSize);
if (oldBuf) {
memcpy(vfm->mem, oldBuf, vfm->size);
mappedMemoryFree(oldBuf, vfm->size);
}
vfm->size = newSize;
}
bool _vfmClose(struct VFile* vf) {
struct VFileMem* vfm = (struct VFileMem*) vf;
vfm->mem = 0;
@ -56,12 +129,23 @@ bool _vfmClose(struct VFile* vf) {
return true;
}
bool _vfmCloseFree(struct VFile* vf) {
struct VFileMem* vfm = (struct VFileMem*) vf;
mappedMemoryFree(vfm->mem, vfm->size);
vfm->mem = 0;
free(vfm);
return true;
}
off_t _vfmSeek(struct VFile* vf, off_t offset, int whence) {
struct VFileMem* vfm = (struct VFileMem*) vf;
size_t position;
switch (whence) {
case SEEK_SET:
if (offset < 0) {
return -1;
}
position = offset;
break;
case SEEK_CUR:
@ -88,6 +172,41 @@ off_t _vfmSeek(struct VFile* vf, off_t offset, int whence) {
return position;
}
off_t _vfmSeekExpanding(struct VFile* vf, off_t offset, int whence) {
struct VFileMem* vfm = (struct VFileMem*) vf;
size_t position;
switch (whence) {
case SEEK_SET:
if (offset < 0) {
return -1;
}
position = offset;
break;
case SEEK_CUR:
if (offset < 0 && ((vfm->offset < (size_t) -offset) || (offset == INT_MIN))) {
return -1;
}
position = vfm->offset + offset;
break;
case SEEK_END:
if (offset < 0 && ((vfm->size < (size_t) -offset) || (offset == INT_MIN))) {
return -1;
}
position = vfm->size + offset;
break;
default:
return -1;
}
if (position > vfm->size) {
_vfmExpand(vfm, position);
}
vfm->offset = position;
return position;
}
ssize_t _vfmRead(struct VFile* vf, void* buffer, size_t size) {
struct VFileMem* vfm = (struct VFileMem*) vf;
@ -112,6 +231,26 @@ ssize_t _vfmWrite(struct VFile* vf, const void* buffer, size_t size) {
return size;
}
ssize_t _vfmWriteExpanding(struct VFile* vf, const void* buffer, size_t size) {
struct VFileMem* vfm = (struct VFileMem*) vf;
if (size + vfm->offset >= vfm->size) {
_vfmExpand(vfm, vfm->offset + size);
}
memcpy((void*) ((uintptr_t) vfm->mem + vfm->offset), buffer, size);
vfm->offset += size;
return size;
}
ssize_t _vfmWriteNoop(struct VFile* vf, const void* buffer, size_t size) {
UNUSED(vf);
UNUSED(buffer);
UNUSED(size);
return -1;
}
void* _vfmMap(struct VFile* vf, size_t size, int flags) {
struct VFileMem* vfm = (struct VFileMem*) vf;
@ -130,6 +269,15 @@ void _vfmUnmap(struct VFile* vf, void* memory, size_t size) {
}
void _vfmTruncate(struct VFile* vf, size_t size) {
struct VFileMem* vfm = (struct VFileMem*) vf;
if (size > vfm->size) {
_vfmExpand(vfm, size);
} else {
// TODO
}
}
void _vfmTruncateNoop(struct VFile* vf, size_t size) {
// TODO: Return value?
UNUSED(vf);
UNUSED(size);