Java tutorial
// Copyright 2014 The Bazel Authors. All rights reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package com.google.devtools.build.lib.packages; import com.google.common.base.Objects; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Lists; import com.google.devtools.build.lib.cmdline.Label; import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable; import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe; import com.google.devtools.build.lib.skylarkinterface.SkylarkModule; import com.google.devtools.build.lib.skylarkinterface.SkylarkValue; import com.google.devtools.build.lib.syntax.Printer; import com.google.devtools.build.lib.util.Preconditions; import com.google.devtools.build.lib.vfs.PathFragment; import java.util.Collection; import java.util.Collections; import java.util.LinkedHashSet; import java.util.List; import java.util.Set; import javax.annotation.Nullable; /** * FilesetEntry is a value object used to represent a "FilesetEntry" inside a "Fileset" BUILD rule. */ @SkylarkModule(name = "FilesetEntry", doc = "", documented = false) @Immutable @ThreadSafe public final class FilesetEntry implements SkylarkValue { public static final SymlinkBehavior DEFAULT_SYMLINK_BEHAVIOR = SymlinkBehavior.COPY; public static final String DEFAULT_STRIP_PREFIX = "."; public static final String STRIP_PREFIX_WORKSPACE = "%workspace%"; @Override public boolean isImmutable() { // TODO(laszlocsomor): set this to true. I think we could do this right now, but am not sure. // Maybe we have to verify that Skylark recognizes every member's type to be recursively // immutable; as of 15/01/2016 this is not true for enum types in general, to name an example. return false; } public static List<String> makeStringList(List<Label> labels) { if (labels == null) { return Collections.emptyList(); } List<String> strings = Lists.newArrayListWithCapacity(labels.size()); for (Label label : labels) { strings.add(label.toString()); } return strings; } public static List<?> makeList(Collection<?> list) { return list == null ? Lists.newArrayList() : Lists.newArrayList(list); } @Override public void write(Appendable buffer, char quotationMark) { Printer.append(buffer, "FilesetEntry(srcdir = "); Printer.write(buffer, getSrcLabel().toString(), quotationMark); Printer.append(buffer, ", files = "); Printer.write(buffer, makeStringList(getFiles()), quotationMark); Printer.append(buffer, ", excludes = "); Printer.write(buffer, makeList(getExcludes()), quotationMark); Printer.append(buffer, ", destdir = "); Printer.write(buffer, getDestDir().getPathString(), quotationMark); Printer.append(buffer, ", strip_prefix = "); Printer.write(buffer, getStripPrefix(), quotationMark); Printer.append(buffer, ", symlinks = "); Printer.append(buffer, quotationMark); Printer.append(buffer, getSymlinkBehavior().toString()); Printer.append(buffer, quotationMark); Printer.append(buffer, ")"); } /** SymlinkBehavior decides what to do when a source file of a FilesetEntry is a symlink. */ @Immutable @ThreadSafe public enum SymlinkBehavior { /** Just copies the symlink as-is. May result in dangling links. */ COPY, /** Follow the link and make the destination point to the absolute path of the final target. */ DEREFERENCE; public static SymlinkBehavior parse(String value) throws IllegalArgumentException { return valueOf(value.toUpperCase()); } @Override public String toString() { return super.toString().toLowerCase(); } } private final Label srcLabel; @Nullable private final ImmutableList<Label> files; @Nullable private final ImmutableSet<String> excludes; private final PathFragment destDir; private final SymlinkBehavior symlinkBehavior; private final String stripPrefix; /** * Constructs a FilesetEntry with the given values. * * @param srcLabel the label of the source directory. Must be non-null. * @param files The explicit files to include. May be null. * @param excludes The files to exclude. Man be null. May only be non-null if files is null. * @param destDir The target-relative output directory. * @param symlinkBehavior how to treat symlinks on the input. See * {@link FilesetEntry.SymlinkBehavior}. * @param stripPrefix the prefix to strip from the package-relative path. If ".", keep only the * basename. */ public FilesetEntry(Label srcLabel, @Nullable List<Label> files, @Nullable Collection<String> excludes, @Nullable String destDir, @Nullable SymlinkBehavior symlinkBehavior, @Nullable String stripPrefix) { this.srcLabel = Preconditions.checkNotNull(srcLabel); this.files = files == null ? null : ImmutableList.copyOf(files); this.excludes = (excludes == null || excludes.isEmpty()) ? null : ImmutableSet.copyOf(excludes); this.destDir = new PathFragment((destDir == null) ? "" : destDir); this.symlinkBehavior = symlinkBehavior == null ? DEFAULT_SYMLINK_BEHAVIOR : symlinkBehavior; this.stripPrefix = stripPrefix == null ? DEFAULT_STRIP_PREFIX : stripPrefix; } /** * @return the source label. */ public Label getSrcLabel() { return srcLabel; } /** * @return the destDir. Non null. */ public PathFragment getDestDir() { return destDir; } /** * @return how symlinks should be handled. */ public SymlinkBehavior getSymlinkBehavior() { return symlinkBehavior; } /** * @return an immutable list of excludes. Null if none specified. */ @Nullable public ImmutableSet<String> getExcludes() { return excludes; } /** * @return an immutable list of file labels. Null if none specified. */ @Nullable public ImmutableList<Label> getFiles() { return files; } /** * @return true if this Fileset should get files from the source directory. */ public boolean isSourceFileset() { return "BUILD".equals(srcLabel.getName()); } /** * @return all prerequisite labels in the FilesetEntry. */ public Collection<Label> getLabels() { Set<Label> labels = new LinkedHashSet<>(); if (files != null) { labels.addAll(files); } else { labels.add(srcLabel); } return labels; } /** * @return the prefix that should be stripped from package-relative path names. */ public String getStripPrefix() { return stripPrefix; } /** * @return null if the entry is valid, and a human-readable error message otherwise. */ @Nullable public String validate() { if (excludes != null && files != null) { return "Cannot specify both 'files' and 'excludes' in a FilesetEntry"; } else if (files != null && !isSourceFileset()) { return "Cannot specify files with Fileset label '" + srcLabel + "'"; } else if (destDir.isAbsolute()) { return "Cannot specify absolute destdir '" + destDir + "'"; } else if (!stripPrefix.equals(DEFAULT_STRIP_PREFIX) && files == null) { return "If the strip prefix is not \"" + DEFAULT_STRIP_PREFIX + "\", files must be specified"; } else if (stripPrefix.startsWith("/")) { return "Cannot specify absolute strip prefix; perhaps you need to use \"" + STRIP_PREFIX_WORKSPACE + "\""; } else if (new PathFragment(stripPrefix).containsUplevelReferences()) { return "Strip prefix must not contain uplevel references"; } else if (stripPrefix.startsWith("%") && !stripPrefix.startsWith(STRIP_PREFIX_WORKSPACE)) { return "If the strip_prefix starts with \"%\" then it must start with \"" + STRIP_PREFIX_WORKSPACE + "\""; } else { return null; } } @Override public String toString() { return String.format( "FilesetEntry(srcdir=%s, destdir=%s, strip_prefix=%s, symlinks=%s, " + "%d file(s) and %d excluded)", srcLabel, destDir, stripPrefix, symlinkBehavior, files != null ? files.size() : 0, excludes != null ? excludes.size() : 0); } @Override public int hashCode() { return Objects.hashCode(srcLabel, files, excludes, destDir, symlinkBehavior, stripPrefix); } @Override public boolean equals(Object other) { if (this == other) { return true; } if (!(other instanceof FilesetEntry)) { return false; } FilesetEntry that = (FilesetEntry) other; return Objects.equal(srcLabel, that.srcLabel) && Objects.equal(files, that.files) && Objects.equal(excludes, that.excludes) && Objects.equal(destDir, that.destDir) && Objects.equal(symlinkBehavior, that.symlinkBehavior) && Objects.equal(stripPrefix, that.stripPrefix); } }