Author: reto
Date: Tue Feb 15 13:52:56 2011
New Revision: 1070898
URL: http://svn.apache.org/viewvc?rev=1070898&view=rev
Log:
CLEREZZA-414: no longer reading datatype and lexical form untill needed
Modified:
incubator/clerezza/trunk/parent/rdf.storage.externalizer/src/main/java/org/apache/clerezza/rdf/storage/externalizer/ExternalizingMGraph.java
Modified:
incubator/clerezza/trunk/parent/rdf.storage.externalizer/src/main/java/org/apache/clerezza/rdf/storage/externalizer/ExternalizingMGraph.java
URL:
http://svn.apache.org/viewvc/incubator/clerezza/trunk/parent/rdf.storage.externalizer/src/main/java/org/apache/clerezza/rdf/storage/externalizer/ExternalizingMGraph.java?rev=1070898&r1=1070897&r2=1070898&view=diff
==============================================================================
---
incubator/clerezza/trunk/parent/rdf.storage.externalizer/src/main/java/org/apache/clerezza/rdf/storage/externalizer/ExternalizingMGraph.java
(original)
+++
incubator/clerezza/trunk/parent/rdf.storage.externalizer/src/main/java/org/apache/clerezza/rdf/storage/externalizer/ExternalizingMGraph.java
Tue Feb 15 13:52:56 2011
@@ -16,7 +16,6 @@
* specific language governing permissions and limitations
* under the License.
*/
-
package org.apache.clerezza.rdf.storage.externalizer;
import java.io.ByteArrayOutputStream;
@@ -50,12 +49,12 @@ import org.slf4j.LoggerFactory;
* AbstractMGraph but intercept the notifictification of the basegraph
*/
class ExternalizingMGraph extends AbstractMGraph {
+
private final MGraph baseGraph;
private final File dataDir;
-
private static final UriRef base64Uri =
new
UriRef("http://www.w3.org/2001/XMLSchema#base64Binary";);
- //not using a nown uri-scheme (such as urn:hash) to avoid collission
with Uris in the graph
+ //not using a known uri-scheme (such as urn:hash) to avoid collission
with Uris in the graph
private static final String UriHashPrefix = "urn:x-litrep:";
private static final Charset UTF8 = Charset.forName("utf-8");
private static final byte[] DELIMITER = "^^".getBytes(UTF8);
@@ -71,7 +70,7 @@ class ExternalizingMGraph extends Abstra
protected Iterator<Triple> performFilter(NonLiteral subject, UriRef
predicate, Resource object) {
if (object != null) {
if (needsReplacing(object)) {
- return
replaceReferences(baseGraph.filter(subject, predicate,
replace((TypedLiteral)object)));
+ return
replaceReferences(baseGraph.filter(subject, predicate, replace((TypedLiteral)
object)));
} else {
return baseGraph.filter(subject, predicate,
object);
}
@@ -99,7 +98,7 @@ class ExternalizingMGraph extends Abstra
Resource object = triple.getObject();
if (needsReplacing(object)) {
return new TripleImpl(triple.getSubject(),
triple.getPredicate(),
- replace((TypedLiteral)object));
+ replace((TypedLiteral) object));
} else {
return triple;
}
@@ -114,7 +113,7 @@ class ExternalizingMGraph extends Abstra
*/
private boolean needsReplacing(Resource object) {
if (object instanceof TypedLiteral) {
- if
(((TypedLiteral)object).getDataType().equals(base64Uri)) {
+ if (((TypedLiteral)
object).getDataType().equals(base64Uri)) {
return true;
}
}
@@ -125,9 +124,7 @@ class ExternalizingMGraph extends Abstra
FileOutputStream out = null;
try {
final byte[] serializedLiteral =
serializeLiteral(literal);
- MessageDigest digest =
java.security.MessageDigest.getInstance("MD5");
- digest.update(serializedLiteral);
- byte[] hash = digest.digest();
+ final byte[] hash = getHash(literal, serializedLiteral);
String base16Hash = toBase16(hash);
File storingFile = getStoringFile(base16Hash);
out = new FileOutputStream(storingFile);
@@ -164,41 +161,9 @@ class ExternalizingMGraph extends Abstra
}
}
- private TypedLiteral parseLiteral(File file) {
+ private TypedLiteral getLiteralForHash(String base16Hash) {
+ return new ReplacementLiteral(base16Hash);
- try {
- InputStream in = new FileInputStream(file);
- try {
- ByteArrayOutputStream typeWriter = new
ByteArrayOutputStream();
- int posInDelimiter = 0;
- for (int ch = in.read(); ch != -1; ch =
in.read()) {
- if (ch == DELIMITER[posInDelimiter]) {
- posInDelimiter++;
- if (DELIMITER.length ==
posInDelimiter) {
- break;
- }
- } else {
- if (posInDelimiter > 0) {
-
typeWriter.write(DELIMITER, 0, posInDelimiter);
- posInDelimiter = 0;
- }
- typeWriter.write(ch);
- }
- }
- UriRef type = new UriRef(new
String(typeWriter.toByteArray(), UTF8));
- typeWriter = null;
- ByteArrayOutputStream dataWriter = new
ByteArrayOutputStream((int) file.length());
- for (int ch = in.read(); ch != -1; ch =
in.read()) {
- dataWriter.write(ch);
- }
- String lexicalForm = new
String(dataWriter.toByteArray(), UTF8);
- return new TypedLiteralImpl(lexicalForm, type);
- } finally {
- in.close();
- }
- } catch (IOException ex) {
- throw new RuntimeException(ex);
- }
}
@@ -214,8 +179,8 @@ class ExternalizingMGraph extends Abstra
}
private File getStoringFile(String base16Hash) {
- File dir1 = new File(dataDir, base16Hash.substring(0,4));
- File dir2 = new File(dir1, base16Hash.substring(4,8));
+ File dir1 = new File(dataDir, base16Hash.substring(0, 4));
+ File dir2 = new File(dir1, base16Hash.substring(4, 8));
dir2.mkdirs();
return new File(dir2, base16Hash.substring(8));
}
@@ -241,15 +206,113 @@ class ExternalizingMGraph extends Abstra
private Triple replaceReference(Triple triple) {
Resource object = triple.getObject();
if (object instanceof UriRef) {
- String uriString =
((UriRef)object).getUnicodeString();
+ String uriString = ((UriRef)
object).getUnicodeString();
if
(uriString.startsWith(UriHashPrefix)) {
- File file =
getStoringFile(uriString.substring(UriHashPrefix.length()));
+ String base16Hash =
uriString.substring(UriHashPrefix.length());
return new
TripleImpl(triple.getSubject(), triple.getPredicate(),
-
parseLiteral(file));
+
getLiteralForHash(base16Hash));
}
}
return triple;
}
};
}
+
+ private byte[] getHash(TypedLiteral literal, byte[] serializedLiteral)
throws NoSuchAlgorithmException {
+ MessageDigest digest =
java.security.MessageDigest.getInstance("MD5");
+ digest.update(serializedLiteral);
+ byte[] hash = new byte[digest.getDigestLength()+4];
+ int javaHash = literal.hashCode();
+ hash[0] = (byte) (javaHash >>> 24);
+ hash[1] = (byte) (javaHash >>> 16);
+ hash[2] = (byte) (javaHash >>> 8);
+ hash[3] = (byte) javaHash;
+ byte[] md5Digest = digest.digest();
+ System.arraycopy(md5Digest, 0, hash, 4, md5Digest.length);
+ return hash;
+ }
+
+ private class ReplacementLiteral implements TypedLiteral {
+
+ private String lexicalForm;
+ private UriRef dataType;
+ final private String base16Hash;
+ private boolean initialized = false;
+ final private int hash;
+
+ private ReplacementLiteral(String base16Hash) {
+ this.base16Hash = base16Hash;
+ hash = Integer.parseInt(base16Hash.substring(0,8), 16);
+ }
+
+ private synchronized void initialize() {
+ if (initialized) {
+ return;
+ }
+ File file = getStoringFile(base16Hash);
+ try {
+ InputStream in = new FileInputStream(file);
+ try {
+ ByteArrayOutputStream typeWriter = new
ByteArrayOutputStream();
+ int posInDelimiter = 0;
+ for (int ch = in.read(); ch != -1; ch =
in.read()) {
+ if (ch ==
DELIMITER[posInDelimiter]) {
+ posInDelimiter++;
+ if (DELIMITER.length ==
posInDelimiter) {
+ break;
+ }
+ } else {
+ if (posInDelimiter > 0)
{
+
typeWriter.write(DELIMITER, 0, posInDelimiter);
+ posInDelimiter
= 0;
+ }
+ typeWriter.write(ch);
+ }
+ }
+ dataType = new UriRef(new
String(typeWriter.toByteArray(), UTF8));
+ typeWriter = null;
+ ByteArrayOutputStream dataWriter = new
ByteArrayOutputStream((int) file.length());
+ for (int ch = in.read(); ch != -1; ch =
in.read()) {
+ dataWriter.write(ch);
+ }
+ lexicalForm = new
String(dataWriter.toByteArray(), UTF8);
+ } finally {
+ in.close();
+ }
+ } catch (IOException ex) {
+ throw new RuntimeException(ex);
+ }
+ initialized = true;
+ }
+
+ @Override
+ public UriRef getDataType() {
+ if (!initialized) initialize();
+ return dataType;
+ }
+
+ @Override
+ public String getLexicalForm() {
+ if (!initialized) initialize();
+ return lexicalForm;
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (obj instanceof ReplacementLiteral) {
+ ReplacementLiteral other =
(ReplacementLiteral)obj;
+ return base16Hash.equals(other.base16Hash);
+ }
+ TypedLiteral other = (TypedLiteral)obj;
+ return getLexicalForm().equals(other.getLexicalForm())
&&
+
getDataType().equals(other.getDataType());
+ }
+
+ @Override
+ public int hashCode() {
+ return hash;
+ }
+
+
+ }
}
