Add byte array implementation to profiler.

explainer/src/main/java/com/google/archivepatcher/explainer/PatchExplainer.java

@@ -29,6 +29,7 @@
 import com.google.archivepatcher.shared.DeflateUncompressor;
 import com.google.archivepatcher.shared.RandomAccessFileInputStream;
 import com.google.archivepatcher.shared.Uncompressor;
+import com.google.archivepatcher.shared.bytesource.ByteSource;
 import java.io.BufferedOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
@@ -119,12 +120,16 @@ public List<EntryExplanation> explainPatch(
     }
 
     Uncompressor uncompressor = new DeflateUncompressor();
-    PreDiffExecutor executor =
-        new PreDiffExecutor.Builder()
-            .readingOriginalFiles(oldFile, newFile)
-            .addPreDiffPlanEntryModifiers(Arrays.asList(preDiffPlanEntryModifiers))
-            .build();
-    PreDiffPlan plan = executor.prepareForDiffing();
+    PreDiffPlan plan;
+    try (ByteSource oldBlob = ByteSource.fromFile(oldFile);
+        ByteSource newBlob = ByteSource.fromFile(newFile)) {
+      PreDiffExecutor executor =
+          new PreDiffExecutor.Builder()
+              .readingOriginalFiles(oldBlob, newBlob)
+              .addPreDiffPlanEntryModifiers(Arrays.asList(preDiffPlanEntryModifiers))
+              .build();
+      plan = executor.prepareForDiffing();
+    }
     try (TempFileHolder oldTemp = new TempFileHolder();
         TempFileHolder newTemp = new TempFileHolder();
         TempFileHolder deltaTemp = new TempFileHolder()) {

explainer/src/test/java/com/google/archivepatcher/explainer/PatchExplainerTest.java

@@ -25,10 +25,10 @@
 import com.google.archivepatcher.shared.Compressor;
 import com.google.archivepatcher.shared.UnitTestZipArchive;
 import com.google.archivepatcher.shared.UnitTestZipEntry;
+import com.google.archivepatcher.shared.bytesource.ByteSource;
 import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -96,7 +96,7 @@ public void compress(InputStream uncompressedIn, OutputStream compressedOut)
    * A "delta generator" that always outputs the same exact string regardless of the inputs and
    * asserts that the input is exactly as expected.
    */
-  private static class FakeDeltaGenerator implements DeltaGenerator {
+  private static class FakeDeltaGenerator extends DeltaGenerator {
     static final String OUTPUT = "fakedeltagenerator output";
     private final byte[] expectedOld;
     private final byte[] expectedNew;
@@ -107,17 +107,18 @@ public FakeDeltaGenerator(byte[] expectedOld, byte[] expectedNew) {
     }
 
     @Override
-    public void generateDelta(File oldBlob, File newBlob, OutputStream deltaOut)
+    public void generateDelta(ByteSource oldBlob, ByteSource newBlob, OutputStream deltaOut)
         throws IOException {
-      assertFileEquals(oldBlob, expectedOld);
-      assertFileEquals(newBlob, expectedNew);
+      assertByteSourceEquals(oldBlob, expectedOld);
+      assertByteSourceEquals(newBlob, expectedNew);
       deltaOut.write(OUTPUT.getBytes("US-ASCII"));
     }
 
-    private final void assertFileEquals(File file, byte[] expected) throws IOException {
-      byte[] actual = new byte[(int) file.length()];
-      try (FileInputStream fileIn = new FileInputStream(file);
-          DataInputStream dataIn = new DataInputStream(fileIn)) {
+    private final void assertByteSourceEquals(ByteSource byteSource, byte[] expected)
+        throws IOException {
+      byte[] actual = new byte[(int) byteSource.length()];
+      try (InputStream in = byteSource.openStream();
+          DataInputStream dataIn = new DataInputStream(in)) {
         dataIn.readFully(actual);
       }
       assertThat(actual).isEqualTo(expected);

generator/src/main/java/com/google/archivepatcher/generator/DefaultDeflateCompressionDiviner.java

@@ -14,12 +14,14 @@
 
 package com.google.archivepatcher.generator;
 
+import static com.google.archivepatcher.shared.bytesource.ByteStreams.readFully;
+
 import com.google.archivepatcher.shared.DefaultDeflateCompatibilityWindow;
 import com.google.archivepatcher.shared.JreDeflateParameters;
+import com.google.archivepatcher.shared.bytesource.ByteSource;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.RandomAccessFile;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -78,7 +80,26 @@ public DivinationResult(
   /**
    * Load the specified archive and attempt to divine deflate parameters for all entries within.
    *
-   * @param archiveFile the archive file to work on
+   * @param archiveBlob the archive blob to work on
+   * @return a list of results for each entry in the archive, in file order (not central directory
+   *     order). There is exactly one result per entry, regardless of whether or not that entry is
+   *     compressed. Callers can filter results by checking {@link
+   *     MinimalZipEntry#getCompressionMethod()} to see if the result is or is not compressed, and
+   *     by checking whether a non-null {@link JreDeflateParameters} was obtained.
+   * @throws IOException if unable to read or parse the file
+   * @see DivinationResult
+   */
+  public static List<DivinationResult> divineDeflateParameters(File archiveBlob)
+      throws IOException {
+    try (ByteSource archiveData = ByteSource.fromFile(archiveBlob)) {
+      return divineDeflateParameters(archiveData);
+    }
+  }
+
+  /**
+   * Load the specified archive and attempt to divine deflate parameters for all entries within.
+   *
+   * @param archiveBlob the archive blob to work on
    * @return a list of results for each entry in the archive, in file order (not central directory
    *     order). There is exactly one result per entry, regardless of whether or not that entry is
    *     compressed. Callers can filter results by checking {@link
@@ -87,10 +108,9 @@ public DivinationResult(
    * @throws IOException if unable to read or parse the file
    * @see DivinationResult
    */
-  public static List<DivinationResult> divineDeflateParameters(File archiveFile)
+  public static List<DivinationResult> divineDeflateParameters(ByteSource archiveBlob)
       throws IOException {
-    RandomAccessFile randomAccessArchiveFile = new RandomAccessFile(archiveFile, "r");
-    List<MinimalZipEntry> zipEntries = MinimalZipArchive.listEntries(archiveFile);
+    List<MinimalZipEntry> zipEntries = MinimalZipArchive.listEntries(archiveBlob);
     List<DivinationResult> results = new ArrayList<>(zipEntries.size());
     for (MinimalZipEntry minimalZipEntry : zipEntries) {
       JreDeflateParameters divinedParameters = null;
@@ -99,47 +119,45 @@ public static List<DivinationResult> divineDeflateParameters(File archiveFile)
         if (minimalZipEntry.getCompressedSize() < (100 * 1024)) {
           try {
             byte[] compressedBytes = new byte[(int) minimalZipEntry.getCompressedSize()];
-            randomAccessArchiveFile.seek(minimalZipEntry.getFileOffsetOfCompressedData());
-            randomAccessArchiveFile.readFully(compressedBytes);
-            divinedParameters =
-                divineDeflateParameters(new ByteArrayInputStreamFactory(compressedBytes));
+            try (InputStream in =
+                archiveBlob
+                    .slice(minimalZipEntry.getFileOffsetOfCompressedData(), compressedBytes.length)
+                    .openStream()) {
+              readFully(in, compressedBytes);
+            }
+            divinedParameters = divineDeflateParametersForEntry(ByteSource.wrap(compressedBytes));
           } catch (Exception ignore) {
             divinedParameters = null;
           }
         } else {
-          divinedParameters =
-              divineDeflateParameters(
-                  new RandomAccessFileInputStreamFactory(
-                      archiveFile,
-                      minimalZipEntry.getFileOffsetOfCompressedData(),
-                      minimalZipEntry.getCompressedSize()));
+          try (ByteSource slice =
+              archiveBlob.slice(
+                  minimalZipEntry.getFileOffsetOfCompressedData(),
+                  minimalZipEntry.getCompressedSize())) {
+            divinedParameters = divineDeflateParametersForEntry(slice);
+          }
         }
       }
       results.add(new DivinationResult(minimalZipEntry, divinedParameters));
     }
-    try {
-      randomAccessArchiveFile.close();
-    } catch (Exception ignore) {
-      // Ignore
-    }
     return results;
   }
 
   /**
    * Determines the original {@link JreDeflateParameters} that were used to compress a given piece
    * of deflated delivery.
    *
-   * @param compressedDataInputStreamFactory a {@link MultiViewInputStreamFactory} that can provide
-   *     multiple independent {@link InputStream} instances for the compressed delivery.
+   * @param entry a {@link MultiViewInputStreamFactory} that can provide multiple independent {@link
+   *     InputStream} instances for the compressed delivery.
    * @return the parameters that can be used to replicate the compressed delivery in the {@link
    *     DefaultDeflateCompatibilityWindow}, if any; otherwise <code>null</code>. Note that <code>
    *     null</code> is also returned in the case of <em>corrupt</em> zip delivery since, by
    *     definition, it cannot be replicated via any combination of normal deflate parameters.
    * @throws IOException if there is a problem reading the delivery, i.e. if the file contents are
    *     changed while reading
    */
-  public static JreDeflateParameters divineDeflateParameters(
-      MultiViewInputStreamFactory compressedDataInputStreamFactory) throws IOException {
+  public static JreDeflateParameters divineDeflateParametersForEntry(ByteSource entry)
+      throws IOException {
     byte[] copyBuffer = new byte[32 * 1024];
     // Iterate over all relevant combinations of nowrap, strategy and level.
     for (boolean nowrap : new boolean[] {true, false}) {
@@ -154,7 +172,7 @@ public static JreDeflateParameters divineDeflateParameters(
           inflater.reset();
           deflater.reset();
           try {
-            if (matches(inflater, deflater, compressedDataInputStreamFactory, copyBuffer)) {
+            if (matches(inflater, deflater, entry, copyBuffer)) {
               end(inflater, deflater);
               return JreDeflateParameters.of(level, strategy, nowrap);
             }
@@ -214,25 +232,21 @@ private static void end(Inflater inflater, Deflater deflater) {
    *
    * @param inflater the inflater for uncompressing the stream
    * @param deflater the deflater for recompressing the output of the inflater
+   * @param compressedData {@link ByteSource} containing the compressed data.
    * @param copyBuffer buffer to use for copying bytes between the inflater and the deflater
    * @return true if the specified deflater reproduces the bytes in compressedDataIn, otherwise
    *     false
    * @throws IOException if anything goes wrong; in particular, {@link ZipException} is thrown if
    *     there is a problem parsing compressedDataIn
    */
   private static boolean matches(
-      Inflater inflater,
-      Deflater deflater,
-      MultiViewInputStreamFactory compressedDataInputStreamFactory,
-      byte[] copyBuffer)
+      Inflater inflater, Deflater deflater, ByteSource compressedData, byte[] copyBuffer)
       throws IOException {
 
     try (MatchingOutputStream matcher =
-            new MatchingOutputStream(
-                compressedDataInputStreamFactory.newStream(), copyBuffer.length);
+            new MatchingOutputStream(compressedData.openStream(), copyBuffer.length);
         InflaterInputStream inflaterIn =
-            new InflaterInputStream(
-                compressedDataInputStreamFactory.newStream(), inflater, copyBuffer.length);
+            new InflaterInputStream(compressedData.openStream(), inflater, copyBuffer.length);
         DeflaterOutputStream out = new DeflaterOutputStream(matcher, deflater, copyBuffer.length)) {
       int numRead;
       while ((numRead = inflaterIn.read(copyBuffer)) >= 0) {

generator/src/main/java/com/google/archivepatcher/generator/DeltaFriendlyOldBlobSizeLimiter.java

@@ -14,7 +14,7 @@
 
 package com.google.archivepatcher.generator;
 
-import java.io.File;
+import com.google.archivepatcher.shared.bytesource.ByteSource;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
@@ -65,7 +65,7 @@ public DeltaFriendlyOldBlobSizeLimiter(long maxSizeBytes) {
 
   @Override
   public List<PreDiffPlanEntry> getModifiedPreDiffPlanEntries(
-      File oldFile, File newFile, List<PreDiffPlanEntry> originalEntries) {
+      ByteSource oldFile, ByteSource newFile, List<PreDiffPlanEntry> originalEntries) {
 
     List<PreDiffPlanEntry> sorted = sortPreDiffPlanEntries(originalEntries);
 

generator/src/main/java/com/google/archivepatcher/generator/DeltaGenerator.java

@@ -14,14 +14,13 @@
 
 package com.google.archivepatcher.generator;
 
+import com.google.archivepatcher.shared.bytesource.ByteSource;
 import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;
 
-/**
- * An interface to be implemented by delta generators.
- */
-public interface DeltaGenerator {
+/** An interface to be implemented by delta generators. */
+public abstract class DeltaGenerator {
   /**
    * Generates a delta in deltaOut that can be applied to oldBlob to produce newBlob.
    *
@@ -32,6 +31,24 @@ public interface DeltaGenerator {
    *     delta output stream
    * @throws InterruptedException if any thread has interrupted the current thread
    */
-  void generateDelta(File oldBlob, File newBlob, OutputStream deltaOut)
+  public void generateDelta(File oldBlob, File newBlob, OutputStream deltaOut)
+      throws IOException, InterruptedException {
+    try (ByteSource oldByteSource = ByteSource.fromFile(oldBlob);
+        ByteSource newByteSource = ByteSource.fromFile(newBlob)) {
+      generateDelta(oldByteSource, newByteSource, deltaOut);
+    }
+  }
+
+  /**
+   * Generates a delta in deltaOut that can be applied to oldBlob to produce newBlob.
+   *
+   * @param oldBlob the old blob
+   * @param newBlob the new blob
+   * @param deltaOut the stream to write the delta to
+   * @throws IOException in the event of an I/O error reading the input files or writing to the
+   *     delta output stream
+   * @throws InterruptedException if any thread has interrupted the current thread
+   */
+  public abstract void generateDelta(ByteSource oldBlob, ByteSource newBlob, OutputStream deltaOut)
       throws IOException, InterruptedException;
 }

generator/src/main/java/com/google/archivepatcher/generator/FileByFileDeltaGenerator.java

@@ -18,6 +18,7 @@
 
 import com.google.archivepatcher.generator.bsdiff.BsDiffDeltaGenerator;
 import com.google.archivepatcher.shared.PatchConstants.DeltaFormat;
+import com.google.archivepatcher.shared.bytesource.ByteSource;
 import java.io.BufferedOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
@@ -30,7 +31,7 @@
 import java.util.Set;
 
 /** Generates file-by-file patches. */
-public class FileByFileDeltaGenerator implements DeltaGenerator {
+public class FileByFileDeltaGenerator extends DeltaGenerator {
 
   /** Modifiers for planning and patch generation. */
   private final List<PreDiffPlanEntryModifier> preDiffPlanEntryModifiers;
@@ -84,14 +85,14 @@ public FileByFileDeltaGenerator(
    * OutputStream} or in a post-processing step, prior to transmitting the patch to the patch
    * applier.
    *
-   * @param oldFile the original old file to read (will not be modified)
-   * @param newFile the original new file to read (will not be modified)
+   * @param oldBlob the original old file to read (will not be modified)
+   * @param newBlob the original new file to read (will not be modified)
    * @param patchOut the stream to write the patch to
    * @throws IOException if unable to complete the operation due to an I/O error
    * @throws InterruptedException if any thread has interrupted the current thread
    */
   @Override
-  public void generateDelta(File oldFile, File newFile, OutputStream patchOut)
+  public void generateDelta(ByteSource oldBlob, ByteSource newBlob, OutputStream patchOut)
       throws IOException, InterruptedException {
     try (TempFileHolder deltaFriendlyOldFile = new TempFileHolder();
         TempFileHolder deltaFriendlyNewFile = new TempFileHolder();
@@ -100,7 +101,7 @@ public void generateDelta(File oldFile, File newFile, OutputStream patchOut)
         BufferedOutputStream bufferedDeltaOut = new BufferedOutputStream(deltaFileOut)) {
       PreDiffPlan preDiffPlan =
           generatePreDiffPlan(
-              oldFile, newFile, deltaFriendlyOldFile, deltaFriendlyNewFile, supportedDeltaFormats);
+              oldBlob, newBlob, deltaFriendlyOldFile, deltaFriendlyNewFile, supportedDeltaFormats);
       DeltaGenerator deltaGenerator = getDeltaGenerator();
       deltaGenerator.generateDelta(
           deltaFriendlyOldFile.file, deltaFriendlyNewFile.file, bufferedDeltaOut);
@@ -124,15 +125,17 @@ public void generateDelta(File oldFile, File newFile, OutputStream patchOut)
    */
   public PreDiffPlan generatePreDiffPlan(File oldFile, File newFile) throws IOException {
     try (TempFileHolder deltaFriendlyOldFile = new TempFileHolder();
-        TempFileHolder deltaFriendlyNewFile = new TempFileHolder()) {
+        TempFileHolder deltaFriendlyNewFile = new TempFileHolder();
+        ByteSource oldBlob = ByteSource.fromFile(oldFile);
+        ByteSource newBlob = ByteSource.fromFile(newFile)) {
       return generatePreDiffPlan(
-          oldFile, newFile, deltaFriendlyOldFile, deltaFriendlyNewFile, supportedDeltaFormats);
+          oldBlob, newBlob, deltaFriendlyOldFile, deltaFriendlyNewFile, supportedDeltaFormats);
     }
   }
 
   private PreDiffPlan generatePreDiffPlan(
-      File oldFile,
-      File newFile,
+      ByteSource oldFile,
+      ByteSource newFile,
       TempFileHolder deltaFriendlyOldFile,
       TempFileHolder deltaFriendlyNewFile,
       Set<DeltaFormat> supportedDeltaFormats)