* The format of the file will be automatically detected and a proper access * implementation for that format will be constructed and returned to the * caller. The file may or may not be held open by the returned instance. * * @param graphFile * existing commit-graph to read. * @return a copy of the commit-graph file in memory * @throws FileNotFoundException * the file does not exist. * @throws CommitGraphFormatException * commit-graph file's format is different from we expected. * @throws java.io.IOException * the file exists but could not be read due to security errors * or unexpected data corruption. */ public static CommitGraph open(File graphFile) throws FileNotFoundException, CommitGraphFormatException, IOException { try (SilentFileInputStream fd = new SilentFileInputStream(graphFile)) { try { return read(fd); } catch (CommitGraphFormatException fe) { throw fe; } catch (IOException ioe) { throw new IOException(MessageFormat.format( JGitText.get().unreadableCommitGraph, graphFile.getAbsolutePath()), ioe); } } } /** * Read an existing commit-graph file from a buffered stream. *
* The format of the file will be automatically detected and a proper access * implementation for that format will be constructed and returned to the * caller. The file may or may not be held open by the returned instance. * * @param fd * stream to read the commit-graph file from. The stream must be * buffered as some small IOs are performed against the stream. * The caller is responsible for closing the stream. * * @return a copy of the commit-graph file in memory * @throws CommitGraphFormatException * the commit-graph file's format is different from we expected. * @throws java.io.IOException * the stream cannot be read. */ public static CommitGraph read(InputStream fd) throws CommitGraphFormatException, IOException { boolean readChangedPathFilters; try { readChangedPathFilters = SystemReader.getInstance().getJGitConfig() .getBoolean(ConfigConstants.CONFIG_COMMIT_GRAPH_SECTION, ConfigConstants.CONFIG_KEY_READ_CHANGED_PATHS, false); } catch (ConfigInvalidException e) { // Use the default value if, for some reason, the config couldn't be // read. readChangedPathFilters = false; } return read(fd, readChangedPathFilters); } /** * Read an existing commit-graph file from a buffered stream. *
* The format of the file will be automatically detected and a proper access
* implementation for that format will be constructed and returned to the
* caller. The file may or may not be held open by the returned instance.
*
* @param fd
* stream to read the commit-graph file from. The stream must be
* buffered as some small IOs are performed against the stream.
* The caller is responsible for closing the stream.
*
* @param readChangedPathFilters
* enable reading bloom filter chunks.
*
* @return a copy of the commit-graph file in memory
* @throws CommitGraphFormatException
* the commit-graph file's format is different from we expected.
* @throws java.io.IOException
* the stream cannot be read.
*/
public static CommitGraph read(InputStream fd,
boolean readChangedPathFilters)
throws CommitGraphFormatException, IOException {
byte[] hdr = new byte[8];
IO.readFully(fd, hdr, 0, hdr.length);
int magic = NB.decodeInt32(hdr, 0);
if (magic != COMMIT_GRAPH_MAGIC) {
throw new CommitGraphFormatException(
JGitText.get().notACommitGraph);
}
// Read the hash version (1 byte)
// 1 => SHA-1
// 2 => SHA-256 nonsupport now
int hashVersion = hdr[5];
if (hashVersion != 1) {
throw new CommitGraphFormatException(
JGitText.get().incorrectOBJECT_ID_LENGTH);
}
// Check commit-graph version
int v = hdr[4];
if (v != 1) {
throw new CommitGraphFormatException(MessageFormat.format(
JGitText.get().unsupportedCommitGraphVersion,
Integer.valueOf(v)));
}
// Read the number of "chunkOffsets" (1 byte)
int numberOfChunks = hdr[6];
// hdr[7] is the number of base commit-graphs, which is not supported in
// current version
byte[] lookupBuffer = new byte[CHUNK_LOOKUP_WIDTH
* (numberOfChunks + 1)];
IO.readFully(fd, lookupBuffer, 0, lookupBuffer.length);
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