1 files changed, 0 insertions, 293 deletions
diff --git a/gerrit-server/src/main/java/com/google/gerrit/rules/RulesCache.java b/gerrit-server/src/main/java/com/google/gerrit/rules/RulesCache.java
deleted file mode 100644
index 9ab0dd65ce..0000000000
--- a/gerrit-server/src/main/java/com/google/gerrit/rules/RulesCache.java
+++ /dev/null
@@ -1,293 +0,0 @@
-// Copyright (C) 2011 The Android Open Source Project
-//
-// 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.gerrit.rules;
-
-import static com.googlecode.prolog_cafe.lang.PrologMachineCopy.save;
-
-import com.google.common.base.Joiner;
-import com.google.common.collect.ImmutableList;
-import com.google.gerrit.extensions.registration.DynamicSet;
-import com.google.gerrit.reviewdb.client.Project;
-import com.google.gerrit.reviewdb.client.RefNames;
-import com.google.gerrit.server.config.GerritServerConfig;
-import com.google.gerrit.server.config.SitePaths;
-import com.google.gerrit.server.git.GitRepositoryManager;
-import com.google.inject.Inject;
-import com.google.inject.Singleton;
-import com.googlecode.prolog_cafe.exceptions.CompileException;
-import com.googlecode.prolog_cafe.exceptions.SyntaxException;
-import com.googlecode.prolog_cafe.exceptions.TermException;
-import com.googlecode.prolog_cafe.lang.BufferingPrologControl;
-import com.googlecode.prolog_cafe.lang.JavaObjectTerm;
-import com.googlecode.prolog_cafe.lang.ListTerm;
-import com.googlecode.prolog_cafe.lang.Prolog;
-import com.googlecode.prolog_cafe.lang.PrologClassLoader;
-import com.googlecode.prolog_cafe.lang.PrologMachineCopy;
-import com.googlecode.prolog_cafe.lang.StructureTerm;
-import com.googlecode.prolog_cafe.lang.SymbolTerm;
-import com.googlecode.prolog_cafe.lang.Term;
-import java.io.IOException;
-import java.io.PushbackReader;
-import java.io.Reader;
-import java.io.StringReader;
-import java.lang.ref.Reference;
-import java.lang.ref.ReferenceQueue;
-import java.lang.ref.WeakReference;
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.net.URLClassLoader;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.ArrayList;
-import java.util.EnumSet;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import org.eclipse.jgit.errors.LargeObjectException;
-import org.eclipse.jgit.lib.Config;
-import org.eclipse.jgit.lib.Constants;
-import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.ObjectLoader;
-import org.eclipse.jgit.lib.Repository;
-import org.eclipse.jgit.util.RawParseUtils;
-
-/**
- * Manages a cache of compiled Prolog rules.
- *
- * <p>Rules are loaded from the {@code site_path/cache/rules/rules-SHA1.jar}, where {@code SHA1} is
- * the SHA1 of the Prolog {@code rules.pl} in a project's {@link RefNames#REFS_CONFIG} branch.
- */
-@Singleton
-public class RulesCache {
-  private static final ImmutableList<String> PACKAGE_LIST =
-      ImmutableList.of(Prolog.BUILTIN, "gerrit");
-
-  private static final class MachineRef extends WeakReference<PrologMachineCopy> {
-    final ObjectId key;
-
-    MachineRef(ObjectId key, PrologMachineCopy pcm, ReferenceQueue<PrologMachineCopy> queue) {
-      super(pcm, queue);
-      this.key = key;
-    }
-  }
-
-  private final boolean enableProjectRules;
-  private final int maxDbSize;
-  private final int maxSrcBytes;
-  private final Path cacheDir;
-  private final Path rulesDir;
-  private final GitRepositoryManager gitMgr;
-  private final DynamicSet<PredicateProvider> predicateProviders;
-  private final ClassLoader systemLoader;
-  private final PrologMachineCopy defaultMachine;
-  private final Map<ObjectId, MachineRef> machineCache = new HashMap<>();
-  private final ReferenceQueue<PrologMachineCopy> dead = new ReferenceQueue<>();
-
-  @Inject
-  protected RulesCache(
-      @GerritServerConfig Config config,
-      SitePaths site,
-      GitRepositoryManager gm,
-      DynamicSet<PredicateProvider> predicateProviders) {
-    maxDbSize = config.getInt("rules", null, "maxPrologDatabaseSize", 256);
-    maxSrcBytes = config.getInt("rules", null, "maxSourceBytes", 128 << 10);
-    enableProjectRules = config.getBoolean("rules", null, "enable", true) && maxSrcBytes > 0;
-    cacheDir = site.resolve(config.getString("cache", null, "directory"));
-    rulesDir = cacheDir != null ? cacheDir.resolve("rules") : null;
-    gitMgr = gm;
-    this.predicateProviders = predicateProviders;
-
-    systemLoader = getClass().getClassLoader();
-    defaultMachine = save(newEmptyMachine(systemLoader));
-  }
-
-  public boolean isProjectRulesEnabled() {
-    return enableProjectRules;
-  }
-
-  /**
-   * Locate a cached Prolog machine state, or create one if not available.
-   *
-   * @return a Prolog machine, after loading the specified rules.
-   * @throws CompileException the machine cannot be created.
-   */
-  public synchronized PrologMachineCopy loadMachine(Project.NameKey project, ObjectId rulesId)
-      throws CompileException {
-    if (!enableProjectRules || project == null || rulesId == null) {
-      return defaultMachine;
-    }
-
-    Reference<? extends PrologMachineCopy> ref = machineCache.get(rulesId);
-    if (ref != null) {
-      PrologMachineCopy pmc = ref.get();
-      if (pmc != null) {
-        return pmc;
-      }
-
-      machineCache.remove(rulesId);
-      ref.enqueue();
-    }
-
-    gc();
-
-    PrologMachineCopy pcm = createMachine(project, rulesId);
-    MachineRef newRef = new MachineRef(rulesId, pcm, dead);
-    machineCache.put(rulesId, newRef);
-    return pcm;
-  }
-
-  public PrologMachineCopy loadMachine(String name, Reader in) throws CompileException {
-    PrologMachineCopy pmc = consultRules(name, in);
-    if (pmc == null) {
-      throw new CompileException("Cannot consult rules from the stream " + name);
-    }
-    return pmc;
-  }
-
-  private void gc() {
-    Reference<?> ref;
-    while ((ref = dead.poll()) != null) {
-      ObjectId key = ((MachineRef) ref).key;
-      if (machineCache.get(key) == ref) {
-        machineCache.remove(key);
-      }
-    }
-  }
-
-  private PrologMachineCopy createMachine(Project.NameKey project, ObjectId rulesId)
-      throws CompileException {
-    // If the rules are available as a complied JAR on local disk, prefer
-    // that over dynamic consult as the bytecode will be faster.
-    //
-    if (rulesDir != null) {
-      Path jarPath = rulesDir.resolve("rules-" + rulesId.getName() + ".jar");
-      if (Files.isRegularFile(jarPath)) {
-        URL[] cp = new URL[] {toURL(jarPath)};
-        return save(newEmptyMachine(new URLClassLoader(cp, systemLoader)));
-      }
-    }
-
-    // Dynamically consult the rules into the machine's internal database.
-    //
-    String rules = read(project, rulesId);
-    PrologMachineCopy pmc = consultRules("rules.pl", new StringReader(rules));
-    if (pmc == null) {
-      throw new CompileException("Cannot consult rules of " + project);
-    }
-    return pmc;
-  }
-
-  private PrologMachineCopy consultRules(String name, Reader rules) throws CompileException {
-    BufferingPrologControl ctl = newEmptyMachine(systemLoader);
-    PushbackReader in = new PushbackReader(rules, Prolog.PUSHBACK_SIZE);
-    try {
-      if (!ctl.execute(
-          Prolog.BUILTIN, "consult_stream", SymbolTerm.intern(name), new JavaObjectTerm(in))) {
-        return null;
-      }
-    } catch (SyntaxException e) {
-      throw new CompileException(e.toString(), e);
-    } catch (TermException e) {
-      Term m = e.getMessageTerm();
-      if (m instanceof StructureTerm && "syntax_error".equals(m.name()) && m.arity() >= 1) {
-        StringBuilder msg = new StringBuilder();
-        if (m.arg(0) instanceof ListTerm) {
-          msg.append(Joiner.on(' ').join(((ListTerm) m.arg(0)).toJava()));
-        } else {
-          msg.append(m.arg(0).toString());
-        }
-        if (m.arity() == 2 && m.arg(1) instanceof StructureTerm && "at".equals(m.arg(1).name())) {
-          Term at = m.arg(1).arg(0).dereference();
-          if (at instanceof ListTerm) {
-            msg.append(" at: ");
-            msg.append(prettyProlog(at));
-          }
-        }
-        throw new CompileException(msg.toString(), e);
-      }
-      throw new CompileException("Error while consulting rules from " + name, e);
-    } catch (RuntimeException e) {
-      throw new CompileException("Error while consulting rules from " + name, e);
-    }
-    return save(ctl);
-  }
-
-  private static String prettyProlog(Term at) {
-    StringBuilder b = new StringBuilder();
-    for (Object o : ((ListTerm) at).toJava()) {
-      if (o instanceof Term) {
-        Term t = (Term) o;
-        if (!(t instanceof StructureTerm)) {
-          b.append(t.toString()).append(' ');
-          continue;
-        }
-        switch (t.name()) {
-          case "atom":
-            SymbolTerm atom = (SymbolTerm) t.arg(0);
-            b.append(atom.toString());
-            break;
-          case "var":
-            b.append(t.arg(0).toString());
-            break;
-        }
-      } else {
-        b.append(o);
-      }
-    }
-    return b.toString().trim();
-  }
-
-  private String read(Project.NameKey project, ObjectId rulesId) throws CompileException {
-    try (Repository git = gitMgr.openRepository(project)) {
-      try {
-        ObjectLoader ldr = git.open(rulesId, Constants.OBJ_BLOB);
-        byte[] raw = ldr.getCachedBytes(maxSrcBytes);
-        return RawParseUtils.decode(raw);
-      } catch (LargeObjectException e) {
-        throw new CompileException("rules of " + project + " are too large", e);
-      } catch (RuntimeException | IOException e) {
-        throw new CompileException("Cannot load rules of " + project, e);
-      }
-    } catch (IOException e) {
-      throw new CompileException("Cannot open repository " + project, e);
-    }
-  }
-
-  private BufferingPrologControl newEmptyMachine(ClassLoader cl) {
-    BufferingPrologControl ctl = new BufferingPrologControl();
-    ctl.setMaxDatabaseSize(maxDbSize);
-    ctl.setPrologClassLoader(
-        new PrologClassLoader(new PredicateClassLoader(predicateProviders, cl)));
-    ctl.setEnabled(EnumSet.allOf(Prolog.Feature.class), false);
-
-    List<String> packages = new ArrayList<>();
-    packages.addAll(PACKAGE_LIST);
-    for (PredicateProvider predicateProvider : predicateProviders) {
-      packages.addAll(predicateProvider.getPackages());
-    }
-
-    // Bootstrap the interpreter and ensure there is clean state.
-    ctl.initialize(packages.toArray(new String[packages.size()]));
-    return ctl;
-  }
-
-  private static URL toURL(Path jarPath) throws CompileException {
-    try {
-      return jarPath.toUri().toURL();
-    } catch (MalformedURLException e) {
-      throw new CompileException("Cannot create URL for " + jarPath, e);
-    }
-  }
-}