VFS: More VFile memory interfaces

src/util/vfs.h

@@ -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);

src/util/vfs/vfs-mem.c

@@ -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);