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Diffstat (limited to 'org.eclipse.jgit/src/org/eclipse/jgit/util/LfsFactory.java')
| -rw-r--r-- | org.eclipse.jgit/src/org/eclipse/jgit/util/LfsFactory.java | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/LfsFactory.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/LfsFactory.java new file mode 100644 index 0000000000..7b7c1d0886 --- /dev/null +++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/LfsFactory.java @@ -0,0 +1,326 @@ +/* + * Copyright (C) 2018, Markus Duft <markus.duft@ssi-schaefer.com> and others + * + * This program and the accompanying materials are made available under the + * terms of the Eclipse Distribution License v. 1.0 which is available at + * https://www.eclipse.org/org/documents/edl-v10.php. + * + * SPDX-License-Identifier: BSD-3-Clause + */ +package org.eclipse.jgit.util; + +import java.io.IOException; +import java.io.InputStream; +import java.io.PrintStream; +import java.text.MessageFormat; +import java.util.concurrent.Callable; + +import org.eclipse.jgit.annotations.Nullable; +import org.eclipse.jgit.attributes.Attribute; +import org.eclipse.jgit.attributes.Attributes; +import org.eclipse.jgit.hooks.PrePushHook; +import org.eclipse.jgit.internal.JGitText; +import org.eclipse.jgit.lib.ObjectLoader; +import org.eclipse.jgit.lib.Repository; +import org.eclipse.jgit.revwalk.RevCommit; +import org.eclipse.jgit.treewalk.FileTreeIterator; +import org.eclipse.jgit.treewalk.TreeWalk; +import org.eclipse.jgit.treewalk.filter.PathFilter; + +/** + * Represents an optionally present LFS support implementation + * + * @since 4.11 + */ +public class LfsFactory { + + private static LfsFactory instance = new LfsFactory(); + + /** + * Constructor + */ + protected LfsFactory() { + } + + /** + * Get the LFS factory instance + * + * @return the current LFS implementation + */ + public static LfsFactory getInstance() { + return instance; + } + + /** + * Set the LFS factory instance + * + * @param instance + * register a {@link LfsFactory} instance as the + * {@link LfsFactory} implementation to use. + */ + public static void setInstance(LfsFactory instance) { + LfsFactory.instance = instance; + } + + /** + * Whether LFS support is available + * + * @return whether LFS support is available + */ + public boolean isAvailable() { + return false; + } + + /** + * Apply clean filtering to the given stream, writing the file content to + * the LFS storage if required and returning a stream to the LFS pointer + * instead. + * + * @param db + * the repository + * @param input + * the original input + * @param length + * the expected input stream length + * @param attribute + * the attribute used to check for LFS enablement (i.e. "merge", + * "diff", "filter" from .gitattributes). + * @return a stream to the content that should be written to the object + * store along with the expected length of the stream. the original + * stream is not applicable. + * @throws IOException + * in case of an error + */ + public LfsInputStream applyCleanFilter(Repository db, + InputStream input, long length, Attribute attribute) + throws IOException { + return new LfsInputStream(input, length); + } + + /** + * Apply smudge filtering to a given loader, potentially redirecting it to a + * LFS blob which is downloaded on demand. + * + * @param db + * the repository + * @param loader + * the loader for the blob + * @param attribute + * the attribute used to check for LFS enablement (i.e. "merge", + * "diff", "filter" from .gitattributes). + * @return a loader for the actual data of a blob, or the original loader in + * case LFS is not applicable. + * @throws IOException + * if an IO error occurred + */ + public ObjectLoader applySmudgeFilter(Repository db, + ObjectLoader loader, Attribute attribute) throws IOException { + return loader; + } + + /** + * Retrieve a pre-push hook to be applied using the default error stream. + * + * @param repo + * the {@link Repository} the hook is applied to. + * @param outputStream + * output stream + * @return a {@link PrePushHook} implementation or <code>null</code> + */ + @Nullable + public PrePushHook getPrePushHook(Repository repo, + PrintStream outputStream) { + return null; + } + + /** + * Retrieve a pre-push hook to be applied. + * + * @param repo + * the {@link Repository} the hook is applied to. + * @param outputStream + * output stream + * @param errorStream + * error stream + * @return a {@link PrePushHook} implementation or <code>null</code> + * @since 5.6 + */ + @Nullable + public PrePushHook getPrePushHook(Repository repo, PrintStream outputStream, + PrintStream errorStream) { + return getPrePushHook(repo, outputStream); + } + + /** + * Retrieve an {@link LfsInstallCommand} which can be used to enable LFS + * support (if available) either per repository or for the user. + * + * @return a command to install LFS support. + */ + @Nullable + public LfsInstallCommand getInstallCommand() { + return null; + } + + /** + * Whether LFS is enabled + * + * @param db + * the repository to check + * @return whether LFS is enabled for the given repository locally or + * globally. + */ + public boolean isEnabled(Repository db) { + return false; + } + + /** + * Get git attributes for given path + * + * @param db + * the repository + * @param path + * the path to find attributes for + * @return the {@link Attributes} for the given path. + * @throws IOException + * in case of an error + */ + public static Attributes getAttributesForPath(Repository db, String path) + throws IOException { + try (TreeWalk walk = new TreeWalk(db)) { + walk.addTree(new FileTreeIterator(db)); + PathFilter f = PathFilter.create(path); + walk.setFilter(f); + walk.setRecursive(false); + Attributes attr = null; + while (walk.next()) { + if (f.isDone(walk)) { + attr = walk.getAttributes(); + break; + } else if (walk.isSubtree()) { + walk.enterSubtree(); + } + } + if (attr == null) { + throw new IOException(MessageFormat + .format(JGitText.get().noPathAttributesFound, path)); + } + + return attr; + } + } + + /** + * Get attributes for given path and commit + * + * @param db + * the repository + * @param path + * the path to find attributes for + * @param commit + * the commit to inspect. + * @return the {@link Attributes} for the given path. + * @throws IOException + * in case of an error + */ + public static Attributes getAttributesForPath(Repository db, String path, + RevCommit commit) throws IOException { + if (commit == null) { + return getAttributesForPath(db, path); + } + + try (TreeWalk walk = TreeWalk.forPath(db, path, commit.getTree())) { + Attributes attr = walk == null ? null : walk.getAttributes(); + if (attr == null) { + throw new IOException(MessageFormat + .format(JGitText.get().noPathAttributesFound, path)); + } + + return attr; + } + } + + /** + * Encapsulate a potentially exchanged {@link InputStream} along with the + * expected stream content length. + */ + public static final class LfsInputStream extends InputStream { + /** + * The actual stream. + */ + private InputStream stream; + + /** + * The expected stream content length. + */ + private long length; + + /** + * Create a new wrapper around a certain stream + * + * @param stream + * the stream to wrap. the stream will be closed on + * {@link #close()}. + * @param length + * the expected length of the stream + */ + public LfsInputStream(InputStream stream, long length) { + this.stream = stream; + this.length = length; + } + + /** + * Create a new wrapper around a temporary buffer. + * + * @param buffer + * the buffer to initialize stream and length from. The + * buffer will be destroyed on {@link #close()} + * @throws IOException + * in case of an error opening the stream to the buffer. + */ + public LfsInputStream(TemporaryBuffer buffer) throws IOException { + this.stream = buffer.openInputStreamWithAutoDestroy(); + this.length = buffer.length(); + } + + @Override + public void close() throws IOException { + stream.close(); + } + + @Override + public int read() throws IOException { + return stream.read(); + } + + @Override + public int read(byte[] b, int off, int len) throws IOException { + return stream.read(b, off, len); + } + + /** + * Get stream length + * + * @return the length of the stream + */ + public long getLength() { + return length; + } + } + + /** + * A command to enable LFS. Optionally set a {@link Repository} to enable + * locally on the repository only. + */ + public interface LfsInstallCommand extends Callable<Void> { + /** + * Set the repository to enable LFS for + * + * @param repo + * the repository to enable support for. + * @return The {@link LfsInstallCommand} for chaining. + */ + public LfsInstallCommand setRepository(Repository repo); + } + +} |