public synchronized SVDBFileSystemDataInput readFile(String path, int id) throws IOException {
SVDBFileSystemDataInput ret = new SVDBFileSystemDataInput();
byte tmp[] = new byte[BLK_SIZE];
FileInfo info = null;
// Read root block
readBlock(path, id, tmp);
ret.addPage(tmp);
int length = ret.readInt(); // Total length of the file
int nblocks = ret.readInt(); // Number of non-root blocks
if (fTrackFiles) {
info = findFileInfo(id);
if (info == null) {
System.out.println("readFile: failed to find id=" + id + " " + path);
try {
throw new Exception();
} catch (Exception e) {
e.printStackTrace();
}
}
if (info != null && nblocks != info.fBlockIdList.size()) {
System.out.println(
"readFile: block count wrong for "
+ id
+ " "
+ path
+ " nblocks="
+ nblocks
+ " actual="
+ info.fBlockIdList.size());
}
}
// Read in the remaining root and storage blocks
for (int i = 0; i < nblocks; i++) {
int block_id = ret.readInt();
if (fTrackFiles && info != null) {
if (block_id != info.fBlockIdList.get(i)) {
System.out.println(
"readFile: block id "
+ i
+ " wrong for "
+ id
+ " "
+ path
+ " block_id="
+ block_id
+ " actual="
+ info.fBlockIdList.get(i));
}
}
tmp = new byte[BLK_SIZE];
readBlock(path, block_id, tmp);
ret.addPage(tmp);
}
int start_idx = ret.getOffset();
ret.setStartIdx(start_idx);
// Compute the initial page and page offset
ret.finalize(length);
return ret;
}
public synchronized void deleteFile(String path, int id) throws IOException {
FileInfo info = null;
SVDBFileSystemDataInput ret = new SVDBFileSystemDataInput();
byte tmp[] = new byte[BLK_SIZE];
if (id < 1) {
throw new IOException("Cannot delete root block");
}
if (fTrackFiles) {
info = findFileInfo(id);
if (info == null) {
System.out.println("deleteFile: failed to find " + id + " " + path);
}
removeFileInfo(info);
}
// Read root block
readBlock(path, id, tmp);
ret.addPage(tmp);
/* int length = */ ret.readInt(); // Total length of the file
int nblocks = ret.readInt(); // Number of non-root blocks
if (nblocks < 0) {}
int blocks_to_read = computeRootBlockCount(nblocks);
if (fTrackFiles && info != null) {
if (nblocks != info.fBlockIdList.size()) {
System.out.println(
"deleteFile: mismatch in blocks for "
+ id
+ " "
+ path
+ " nblocks="
+ nblocks
+ " actual="
+ info.fBlockIdList.size());
}
}
// Read in the remaining block ids and free them
for (int i = 0; i < nblocks; i++) {
int block_id = ret.readInt();
if (fTrackFiles && info != null) {
if (block_id != info.fBlockIdList.get(i)) {
System.out.println(
"deleteFile: block "
+ i
+ " mismatch "
+ "block_id="
+ block_id
+ " actual="
+ info.fBlockIdList.get(i));
}
}
if (i < blocks_to_read) {
tmp = new byte[BLK_SIZE];
readBlock(path, block_id, tmp);
ret.addPage(tmp);
}
freeBlock(block_id);
}
freeBlock(id);
}
private boolean open_filesystem(File f) throws IOException {
boolean ret = true;
RandomAccessFile rw = null;
rw = new RandomAccessFile(f, "rw");
fFileRWList.add(rw);
// Read the root block
byte tmp[] = new byte[BLK_SIZE];
readBlock("rootFile", 0, tmp);
SVDBFileSystemDataInput in = new SVDBFileSystemDataInput();
in.addPage(tmp);
/**
* Root block is: - Magic number - Filesystem version-string length - Filesystem version
* (string) - Number of storage files in this filesystem - Block length of the last file -
* Handle to the alloc list - Alloc list length - Handle to the file-info list - File-info list
* length - user data length - user data
*/
int magic_number = in.readInt();
if (magic_number != VALID_MAGIC_NUMBER) {
ret = false;
} else {
String version = in.readString();
if (!fVersion.equals(version)) {
// Version doesn't match, so re-initialize the filesystem
ret = false;
cleanup();
initialize();
} else {
int n_files = in.readInt();
fLastRwBlkLen = in.readInt();
fAllocListFile = in.readInt();
int alloc_list_len = in.readInt();
// Read back the file list;
fFileInfoHndl = in.readInt();
int file_list_size = in.readInt();
if (fTrackFiles) {
fTrackFiles = false;
SVDBFileSystemDataInput file_info_in = readFile("fileInfo", fFileInfoHndl);
fTrackFiles = true;
fFileList.clear();
for (int i = 0; i < file_list_size; i++) {
FileInfo info = new FileInfo();
info.fFileId = file_info_in.readInt();
int n_blocks = file_info_in.readInt();
for (int j = 0; j < n_blocks; j++) {
info.fBlockIdList.add(file_info_in.readInt());
}
fFileList.add(info);
}
}
int ud_len = in.readInt();
if (ud_len == -1) {
fUserData = null;
} else {
fUserData = new byte[ud_len];
in.readFully(fUserData);
}
for (int i = 2; i <= n_files; i++) {
f = new File(fDBDir, i + ".db");
rw = new RandomAccessFile(f, "rw");
fFileRWList.add(rw);
}
// Now we can read in the alloc list and initialize the AllocList
boolean track_files = fTrackFiles;
fTrackFiles = false;
SVDBFileSystemDataInput alloc_in = readFile("allocList", fAllocListFile);
fTrackFiles = track_files;
fAllocList = new byte[alloc_list_len];
alloc_in.readFully(fAllocList);
if (fTrackFiles) {
for (int i = 0; i < fAllocList.length; i++) {
if ((i % 16) == 0) {
if (i != 0) {
System.out.println();
}
System.out.print("" + i + ": ");
}
System.out.print(Integer.toHexString(fAllocList[i]) + " ");
}
System.out.println();
System.out.println("--> Validate Initial Load alloc_list_len=" + alloc_list_len);
removeFileInfo(null);
System.out.println("<-- Validate Initial Load");
}
}
}
if (ret) {
// Mark the filesystem as open and invalid. This enables us to
// detect filesystem invalidity due to improper close
write32(0, tmp, ~VALID_MAGIC_NUMBER);
writeBlock("rootBlock", 0, tmp);
}
return ret;
}