diff options
Diffstat (limited to 'gerrit-server/src/main/java/com/google/gerrit/server/patch/IntraLineLoader.java')
| -rw-r--r-- | gerrit-server/src/main/java/com/google/gerrit/server/patch/IntraLineLoader.java | 325 |
1 files changed, 0 insertions, 325 deletions
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/patch/IntraLineLoader.java b/gerrit-server/src/main/java/com/google/gerrit/server/patch/IntraLineLoader.java deleted file mode 100644 index f17f0b6856..0000000000 --- a/gerrit-server/src/main/java/com/google/gerrit/server/patch/IntraLineLoader.java +++ /dev/null @@ -1,325 +0,0 @@ -// Copyright (C) 2009 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.server.patch; - -import com.google.common.base.Throwables; -import com.google.common.collect.ImmutableList; -import com.google.common.collect.ImmutableSet; -import com.google.gerrit.server.config.ConfigUtil; -import com.google.gerrit.server.config.GerritServerConfig; -import com.google.inject.Inject; -import com.google.inject.assistedinject.Assisted; -import java.util.ArrayList; -import java.util.List; -import java.util.concurrent.Callable; -import java.util.concurrent.ExecutionException; -import java.util.concurrent.ExecutorService; -import java.util.concurrent.Future; -import java.util.concurrent.TimeUnit; -import java.util.concurrent.TimeoutException; -import java.util.regex.Pattern; -import org.eclipse.jgit.diff.Edit; -import org.eclipse.jgit.diff.MyersDiff; -import org.eclipse.jgit.diff.ReplaceEdit; -import org.eclipse.jgit.lib.Config; -import org.slf4j.Logger; -import org.slf4j.LoggerFactory; - -class IntraLineLoader implements Callable<IntraLineDiff> { - static final Logger log = LoggerFactory.getLogger(IntraLineLoader.class); - - interface Factory { - IntraLineLoader create(IntraLineDiffKey key, IntraLineDiffArgs args); - } - - private static final Pattern BLANK_LINE_RE = - Pattern.compile("^[ \\t]*(|[{}]|/\\*\\*?|\\*)[ \\t]*$"); - - private static final Pattern CONTROL_BLOCK_START_RE = Pattern.compile("[{:][ \\t]*$"); - - private final ExecutorService diffExecutor; - private final long timeoutMillis; - private final IntraLineDiffKey key; - private final IntraLineDiffArgs args; - - @Inject - IntraLineLoader( - @DiffExecutor ExecutorService diffExecutor, - @GerritServerConfig Config cfg, - @Assisted IntraLineDiffKey key, - @Assisted IntraLineDiffArgs args) { - this.diffExecutor = diffExecutor; - timeoutMillis = - ConfigUtil.getTimeUnit( - cfg, - "cache", - PatchListCacheImpl.INTRA_NAME, - "timeout", - TimeUnit.MILLISECONDS.convert(5, TimeUnit.SECONDS), - TimeUnit.MILLISECONDS); - this.key = key; - this.args = args; - } - - @Override - public IntraLineDiff call() throws Exception { - Future<IntraLineDiff> result = - diffExecutor.submit( - () -> - IntraLineLoader.compute( - args.aText(), args.bText(), args.edits(), args.editsDueToRebase())); - try { - return result.get(timeoutMillis, TimeUnit.MILLISECONDS); - } catch (InterruptedException | TimeoutException e) { - log.warn( - timeoutMillis - + " ms timeout reached for IntraLineDiff" - + " in project " - + args.project() - + " on commit " - + args.commit().name() - + " for path " - + args.path() - + " comparing " - + key.getBlobA().name() - + ".." - + key.getBlobB().name()); - result.cancel(true); - return new IntraLineDiff(IntraLineDiff.Status.TIMEOUT); - } catch (ExecutionException e) { - // If there was an error computing the result, carry it - // up to the caller so the cache knows this key is invalid. - Throwables.throwIfInstanceOf(e.getCause(), Exception.class); - throw new Exception(e.getMessage(), e.getCause()); - } - } - - static IntraLineDiff compute( - Text aText, - Text bText, - ImmutableList<Edit> immutableEdits, - ImmutableSet<Edit> immutableEditsDueToRebase) { - List<Edit> edits = new ArrayList<>(immutableEdits); - combineLineEdits(edits, immutableEditsDueToRebase, aText, bText); - - for (int i = 0; i < edits.size(); i++) { - Edit e = edits.get(i); - - if (e.getType() == Edit.Type.REPLACE) { - CharText a = new CharText(aText, e.getBeginA(), e.getEndA()); - CharText b = new CharText(bText, e.getBeginB(), e.getEndB()); - CharTextComparator cmp = new CharTextComparator(); - - List<Edit> wordEdits = MyersDiff.INSTANCE.diff(cmp, a, b); - - // Combine edits that are really close together. If they are - // just a few characters apart we tend to get better results - // by joining them together and taking the whole span. - // - for (int j = 0; j < wordEdits.size() - 1; ) { - Edit c = wordEdits.get(j); - Edit n = wordEdits.get(j + 1); - - if (n.getBeginA() - c.getEndA() <= 5 || n.getBeginB() - c.getEndB() <= 5) { - int ab = c.getBeginA(); - int ae = n.getEndA(); - - int bb = c.getBeginB(); - int be = n.getEndB(); - - if (canCoalesce(a, c.getEndA(), n.getBeginA()) - && canCoalesce(b, c.getEndB(), n.getBeginB())) { - wordEdits.set(j, new Edit(ab, ae, bb, be)); - wordEdits.remove(j + 1); - continue; - } - } - - j++; - } - - // Apply some simple rules to fix up some of the edits. Our - // logic above, along with our per-character difference tends - // to produce some crazy stuff. - // - for (int j = 0; j < wordEdits.size(); j++) { - Edit c = wordEdits.get(j); - int ab = c.getBeginA(); - int ae = c.getEndA(); - - int bb = c.getBeginB(); - int be = c.getEndB(); - - // Sometimes the diff generator produces an INSERT or DELETE - // right up against a REPLACE, but we only find this after - // we've also played some shifting games on the prior edit. - // If that happened to us, coalesce them together so we can - // correct this mess for the user. If we don't we wind up - // with silly stuff like "es" -> "es = Addresses". - // - if (1 < j) { - Edit p = wordEdits.get(j - 1); - if (p.getEndA() == ab || p.getEndB() == bb) { - if (p.getEndA() == ab && p.getBeginA() < p.getEndA()) { - ab = p.getBeginA(); - } - if (p.getEndB() == bb && p.getBeginB() < p.getEndB()) { - bb = p.getBeginB(); - } - wordEdits.remove(--j); - } - } - - // We sometimes collapsed an edit together in a strange way, - // such that the edges of each text is identical. Fix by - // by dropping out that incorrectly replaced region. - // - while (ab < ae && bb < be && cmp.equals(a, ab, b, bb)) { - ab++; - bb++; - } - while (ab < ae && bb < be && cmp.equals(a, ae - 1, b, be - 1)) { - ae--; - be--; - } - - // The leading part of an edit and its trailing part in the same - // text might be identical. Slide down that edit and use the tail - // rather than the leading bit. - // - while (0 < ab - && ab < ae - && a.charAt(ab - 1) != '\n' - && cmp.equals(a, ab - 1, a, ae - 1)) { - ab--; - ae--; - } - if (!a.isLineStart(ab) || !a.contains(ab, ae, '\n')) { - while (ab < ae && ae < a.size() && cmp.equals(a, ab, a, ae)) { - ab++; - ae++; - if (a.charAt(ae - 1) == '\n') { - break; - } - } - } - - while (0 < bb - && bb < be - && b.charAt(bb - 1) != '\n' - && cmp.equals(b, bb - 1, b, be - 1)) { - bb--; - be--; - } - if (!b.isLineStart(bb) || !b.contains(bb, be, '\n')) { - while (bb < be && be < b.size() && cmp.equals(b, bb, b, be)) { - bb++; - be++; - if (b.charAt(be - 1) == '\n') { - break; - } - } - } - - // If most of a line was modified except the LF was common, make - // the LF part of the modification region. This is easier to read. - // - if (ab < ae // - && (ab == 0 || a.charAt(ab - 1) == '\n') // - && ae < a.size() - && a.charAt(ae - 1) != '\n' - && a.charAt(ae) == '\n') { - ae++; - } - if (bb < be // - && (bb == 0 || b.charAt(bb - 1) == '\n') // - && be < b.size() - && b.charAt(be - 1) != '\n' - && b.charAt(be) == '\n') { - be++; - } - - wordEdits.set(j, new Edit(ab, ae, bb, be)); - } - - edits.set(i, new ReplaceEdit(e, wordEdits)); - } - } - - return new IntraLineDiff(edits); - } - - private static void combineLineEdits( - List<Edit> edits, ImmutableSet<Edit> editsDueToRebase, Text a, Text b) { - for (int j = 0; j < edits.size() - 1; ) { - Edit c = edits.get(j); - Edit n = edits.get(j + 1); - - if (editsDueToRebase.contains(c) || editsDueToRebase.contains(n)) { - // Don't combine any edits which were identified as being introduced by a rebase as we would - // lose that information because of the combination. - j++; - continue; - } - - // Combine edits that are really close together. Right now our rule - // is, coalesce two line edits which are only one line apart if that - // common context line is either a "pointless line", or is identical - // on both sides and starts a new block of code. These are mostly - // block reindents to add or remove control flow operators. - // - final int ad = n.getBeginA() - c.getEndA(); - final int bd = n.getBeginB() - c.getEndB(); - if ((1 <= ad && isBlankLineGap(a, c.getEndA(), n.getBeginA())) - || (1 <= bd && isBlankLineGap(b, c.getEndB(), n.getBeginB())) - || (ad == 1 && bd == 1 && isControlBlockStart(a, c.getEndA()))) { - int ab = c.getBeginA(); - int ae = n.getEndA(); - - int bb = c.getBeginB(); - int be = n.getEndB(); - - edits.set(j, new Edit(ab, ae, bb, be)); - edits.remove(j + 1); - continue; - } - - j++; - } - } - - private static boolean isBlankLineGap(Text a, int b, int e) { - for (; b < e; b++) { - if (!BLANK_LINE_RE.matcher(a.getString(b)).matches()) { - return false; - } - } - return true; - } - - private static boolean isControlBlockStart(Text a, int idx) { - return CONTROL_BLOCK_START_RE.matcher(a.getString(idx)).find(); - } - - private static boolean canCoalesce(CharText a, int b, int e) { - while (b < e) { - if (a.charAt(b++) == '\n') { - return false; - } - } - return true; - } -} |