GoogleJsMessageIdGenerator.java
/*
* Copyright 2008 The Closure Compiler Authors.
*
* 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.javascript.jscomp;
import static com.google.common.base.Preconditions.checkState;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.common.base.CaseFormat;
import com.google.common.base.Strings;
import com.google.javascript.jscomp.JsMessage.IdGenerator;
import com.google.javascript.jscomp.JsMessage.PlaceholderReference;
import java.util.List;
/**
* An {@link IdGenerator} designed to play nicely with Google's Translation
* systems. Each message is scoped to a project id, so that it does
* not conflict with other messages at Google.
* <p>
* Just as reminder what key type used in different formats:
* <ol>
* <li>XMB - id. We export using this format.
* <li>XTB - id. Internal, result of translation.
* <li>XLB - name. External, use it if we need to share translation with third
* part.
* <li>PROPERTIES - name.
* </ol>
*
* @see <a href="http://cldr.unicode.org/development/development-process/design-proposals/xmb">xmb</a>
*/
public final class GoogleJsMessageIdGenerator implements IdGenerator {
private final String projectId;
/**
* Creates an instance.
*
* @param projectId A TC project name (e.g. "MyProject")
*/
public GoogleJsMessageIdGenerator(String projectId) {
this.projectId = projectId;
}
@Override
public String generateId(String meaning, List<CharSequence> messageParts) {
checkState(meaning != null);
StringBuilder sb = new StringBuilder();
for (CharSequence part : messageParts) {
if (part instanceof PlaceholderReference) {
sb.append(CaseFormat.LOWER_CAMEL.to(
CaseFormat.UPPER_UNDERSCORE,
((PlaceholderReference) part).getName()));
} else {
sb.append(part);
}
}
String tcValue = sb.toString();
String projectScopedMeaning =
(Strings.isNullOrEmpty(projectId) ? "" : (projectId + ": ")) + meaning;
return String.valueOf(
MessageId.generateId(tcValue, projectScopedMeaning));
}
/**
* 64-bit fingerprint support.
*
* Forked from the guava-internal library.
*/
private static final class FP {
private FP() {}
/** Generate fingerprint of "byte[start,limit-1]". */
private static long fingerprint(byte[] str, int start, int limit) {
int hi = hash32(str, start, limit, 0);
int lo = hash32(str, start, limit, 102072);
if ((hi == 0) && (lo == 0 || lo == 1)) {
// Turn 0/1 into another fingerprint
hi ^= 0x130f9bef;
lo ^= 0x94a0a928;
}
return (((long) hi) << 32) | (lo & 0xffffffffL);
}
/**
* Generate fingerprint of "str". Equivalent to UTF-encoding "str" into
* bytes and then fingerprinting those bytes.
*/
private static long fingerprint(String str) {
byte[] tmp = str.getBytes(UTF_8);
return FP.fingerprint(tmp, 0, tmp.length);
}
@SuppressWarnings("fallthrough")
private static int hash32(byte[] str, int start, int limit, int c) {
int a = 0x9e3779b9;
int b = 0x9e3779b9;
int i;
for (i = start; i + 12 <= limit; i += 12) {
a += (((str[i + 0] & 0xff) << 0)
| ((str[i + 1] & 0xff) << 8)
| ((str[i + 2] & 0xff) << 16)
| ((str[i + 3] & 0xff) << 24));
b += (((str[i + 4] & 0xff) << 0)
| ((str[i + 5] & 0xff) << 8)
| ((str[i + 6] & 0xff) << 16)
| ((str[i + 7] & 0xff) << 24));
c += (((str[i + 8] & 0xff) << 0)
| ((str[i + 9] & 0xff) << 8) | ((str[i + 10] & 0xff) << 16)
| ((str[i + 11] & 0xff) << 24));
// Mix
a -= b;
a -= c;
a ^= (c >>> 13);
b -= c;
b -= a;
b ^= (a << 8);
c -= a;
c -= b;
c ^= (b >>> 13);
a -= b;
a -= c;
a ^= (c >>> 12);
b -= c;
b -= a;
b ^= (a << 16);
c -= a;
c -= b;
c ^= (b >>> 5);
a -= b;
a -= c;
a ^= (c >>> 3);
b -= c;
b -= a;
b ^= (a << 10);
c -= a;
c -= b;
c ^= (b >>> 15);
}
c += limit - start;
int tmp = limit - i;
if (tmp == 11) {
c += (str[i + 10] & 0xff) << 24;
}
if (tmp >= 10) {
c += (str[i + 9] & 0xff) << 16;
}
if (tmp >= 9) {
c += (str[i + 8] & 0xff) << 8;
// the first byte of c is reserved for the length
}
if (tmp >= 8) {
b += (str[i + 7] & 0xff) << 24;
}
if (tmp >= 7) {
b += (str[i + 6] & 0xff) << 16;
}
if (tmp >= 6) {
b += (str[i + 5] & 0xff) << 8;
}
if (tmp >= 5) {
b += (str[i + 4] & 0xff);
}
if (tmp >= 4) {
a += (str[i + 3] & 0xff) << 24;
}
if (tmp >= 3) {
a += (str[i + 2] & 0xff) << 16;
}
if (tmp >= 2) {
a += (str[i + 1] & 0xff) << 8;
}
if (tmp >= 1) {
a += (str[i + 0] & 0xff);
// case 0 : nothing left to add
}
// Mix
a -= b;
a -= c;
a ^= (c >>> 13);
b -= c;
b -= a;
b ^= (a << 8);
c -= a;
c -= b;
c ^= (b >>> 13);
a -= b;
a -= c;
a ^= (c >>> 12);
b -= c;
b -= a;
b ^= (a << 16);
c -= a;
c -= b;
c ^= (b >>> 5);
a -= b;
a -= c;
a ^= (c >>> 3);
b -= c;
b -= a;
b ^= (a << 10);
c -= a;
c -= b;
c ^= (b >>> 15);
return c;
}
}
/**
* Generates fingerprint for an English message using the FP package.
* This supersedes the message id generation using C fingerprint
* functions and JNI. This is slower than the C implementation (
* we're talking about microseconds here) but it avoids using JNI and
* shared libraries.<p>
*
* Forked from the i18n library.
*/
private static class MessageId {
private static final long generateId(String message, String meaning) {
long fp = FP.fingerprint(message);
if (null != meaning && meaning.length() > 0) {
// combine the fingerprints of message and meaning
long fp2 = FP.fingerprint(meaning);
fp = fp2 + (fp << 1) + (fp < 0 ? 1 : 0);
}
// To avoid negative ids we strip the high-order bit
return fp & 0x7fffffffffffffffL;
}
}
}