Use Apache Commons for reading tar files

Fixes #305.

--
MOS_MIGRATED_REVID=98730375

2 files changed, 11 insertions, 177 deletions

diff --git a/src/main/java/BUILD b/src/main/java/BUILD
index a8252ab8eb..25aa0edb5e 100644
--- a/src/main/java/BUILD
+++ b/src/main/java/BUILD
@@ -451,6 +451,7 @@ java_library(
         "//src/main/protobuf:proto_test_status",
         "//src/main/protobuf:proto_worker_protocol",
         "//third_party:aether",
+        "//third_party:apache_commons_compress",
         "//third_party:apache_commons_pool2",
         "//third_party:auto_value",
         "//third_party:guava",
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/TarGzFunction.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/TarGzFunction.java
index 85100001f9..81be03d587 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/TarGzFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/TarGzFunction.java
@@ -14,7 +14,6 @@
 
 package com.google.devtools.build.lib.bazel.repository;
 
-import com.google.common.io.CountingInputStream;
 import com.google.devtools.build.lib.bazel.repository.DecompressorValue.DecompressorDescriptor;
 import com.google.devtools.build.lib.bazel.repository.RepositoryFunction.RepositoryFunctionException;
 import com.google.devtools.build.lib.vfs.FileSystemUtils;
@@ -22,12 +21,15 @@ import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.skyframe.SkyFunction;
 import com.google.devtools.build.skyframe.SkyFunctionException.Transience;
 import com.google.devtools.build.skyframe.SkyFunctionName;
+
 import com.google.devtools.build.skyframe.SkyKey;
 import com.google.devtools.build.skyframe.SkyValue;
 
+import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
+import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
+
 import java.io.FileInputStream;
 import java.io.IOException;
-import java.io.InputStream;
 import java.nio.file.Files;
 import java.util.zip.GZIPInputStream;
 
@@ -47,16 +49,16 @@ public class TarGzFunction implements SkyFunction {
 
     try (GZIPInputStream gzipStream = new GZIPInputStream(
         new FileInputStream(descriptor.archivePath().getPathFile()))) {
-      TarInputStream inputStream = new TarInputStream(gzipStream);
-      while (inputStream.available() != 0) {
-        TarEntry entry = inputStream.getNextEntry();
-        Path filename = descriptor.repositoryPath().getRelative(entry.getFilename());
+      TarArchiveInputStream tarStream = new TarArchiveInputStream(gzipStream);
+      TarArchiveEntry entry;
+      while ((entry = tarStream.getNextTarEntry()) != null) {
+        Path filename = descriptor.repositoryPath().getRelative(entry.getName());
         FileSystemUtils.createDirectoryAndParents(filename.getParentDirectory());
         if (entry.isDirectory()) {
           FileSystemUtils.createDirectoryAndParents(filename);
         } else {
-          Files.copy(entry, filename.getPathFile().toPath());
-          filename.chmod(entry.getPermissions());
+          Files.copy(tarStream, filename.getPathFile().toPath());
+          filename.chmod(entry.getMode());
         }
       }
     } catch (IOException e) {
@@ -71,173 +73,4 @@ public class TarGzFunction implements SkyFunction {
     return null;
   }
 
-  private static class TarInputStream {
-    private final CountingInputStream inputStream;
-    private String nextFilename;
-
-    public TarInputStream(InputStream inputStream) {
-      this.inputStream = new CountingInputStream(inputStream);
-    }
-
-    public int available() throws IOException {
-      nextFilename = TarEntry.parseFilename(inputStream);
-      if (nextFilename.isEmpty()) {
-        // We've probably reached the padding at the end of the .tar file.
-        return 0;
-      }
-      return inputStream.available();
-    }
-
-    public TarEntry getNextEntry() throws IOException {
-      return new TarEntry(nextFilename, inputStream);
-    }
-  }
-
-  private static class TarEntry extends InputStream {
-    private static final int BUFFER_SIZE = 512;
-    private static final int FILENAME_SIZE = 100;
-    private static final int PERMISSIONS_SIZE = 8;
-    private static final int FILE_SIZE = 12;
-    private static final int TYPE_SIZE = 1;
-    private static final int USTAR_SIZE = 6;
-
-    public enum FileType {
-      NORMAL, DIRECTORY
-    }
-
-    private final String filename;
-    private final int permissions;
-    private final FileType type;
-    private final CountingInputStream inputStream;
-    // Tar format pads the content to blocks of 512 bytes, so when we're done reading the file skip
-    // this many bytes to arrive at the next file.
-    private final int finalSkip;
-    private long bytesRemaining;
-    private boolean done;
-
-    public TarEntry(String filename, CountingInputStream inputStream) throws IOException {
-      byte buffer[] = new byte[BUFFER_SIZE];
-
-      this.filename = filename;
-
-      // Permissions.
-      if (inputStream.read(buffer, 0, PERMISSIONS_SIZE) != PERMISSIONS_SIZE) {
-        throw new IOException("Error reading tar file (could not read permissions for " + filename
-            + ")");
-      }
-
-      String permissionsString;
-      if (buffer[PERMISSIONS_SIZE - 2] == ' ') {
-        // The permissions look like 000644 \0 (OS X, sigh).
-        permissionsString = new String(buffer, 0, PERMISSIONS_SIZE - 2);
-      } else {
-        // The permissions look like 0000644\0 (Linux).
-        permissionsString = new String(buffer, 0, PERMISSIONS_SIZE - 1);
-      }
-      try {
-        permissions = Integer.parseInt(permissionsString, 8);
-      } catch (NumberFormatException e) {
-        throw new IOException("Error reading tar file (could not parse permissions of " + filename
-            + "): [" + permissionsString + "]");
-      }
-
-      // User & group IDs.
-      inputStream.skip(16);
-
-      // File size.
-      if (inputStream.read(buffer, 0, FILE_SIZE) != FILE_SIZE) {
-        throw new IOException("Error reading tar file (could not read file size of " + filename
-            + ")");
-      }
-
-      // 12345678901\0 in base 8, bizarly.
-      bytesRemaining = Long.parseLong(new String(buffer, 0, FILE_SIZE - 1), 8);
-      if (bytesRemaining % 512 == 0) {
-        if (bytesRemaining == 0) {
-          done = true;
-        }
-        finalSkip = 0;
-      } else {
-        done = false;
-        finalSkip = (int) (512 - bytesRemaining % 512);
-      }
-
-      // Timestamp and checksum.
-      // TODO(kchodorow): actually check the checksum.
-      inputStream.skip(20);
-
-      if (inputStream.read(buffer, 0, TYPE_SIZE) != TYPE_SIZE) {
-        throw new IOException("Error reading tar file (could not read file type of " + filename
-            + ")");
-      }
-      char type = (char) buffer[0];
-      if (type == '0') {
-        this.type = FileType.NORMAL;
-      } else if (type == '5') {
-        this.type = FileType.DIRECTORY;
-      } else {
-        // TODO(kchodorow): support links.
-        throw new IOException("Error reading tar file (unknown file type " + type + " for file "
-            + filename + ")");
-      }
-
-      // Skip name of linked file.
-      inputStream.skip(100);
-
-      // USTAR constant.
-      if (inputStream.read(buffer, 0, USTAR_SIZE) != USTAR_SIZE
-          || !new String(buffer, 0, USTAR_SIZE - 1).equals("ustar")) {
-        // TODO(kchodorow): support old-style tar format.
-        throw new IOException("Error reading tar file (" + filename + " did not specify 'ustar')");
-      }
-
-      // Skip the rest of the ustar preamble.
-      inputStream.skip(249);
-      // We're now at position 512.
-
-      // Ready to read content.
-      this.inputStream = inputStream;
-    }
-
-    private static String parseFilename(InputStream inputStream) throws IOException {
-      byte buffer[] = new byte[FILENAME_SIZE];
-
-      if (inputStream.read(buffer, 0, FILENAME_SIZE) != FILENAME_SIZE) {
-        throw new IOException("Error reading tar file (could not read filename)");
-      }
-
-      int actualFilenameLength = 0;
-      while (actualFilenameLength < FILENAME_SIZE) {
-        if (buffer[actualFilenameLength] == 0) {
-          break;
-        }
-        actualFilenameLength++;
-      }
-      return new String(buffer, 0, actualFilenameLength);
-    }
-
-    public String getFilename() {
-      return filename;
-    }
-
-    public int getPermissions() {
-      return permissions;
-    }
-
-    public boolean isDirectory() {
-      return type == FileType.DIRECTORY;
-    }
-
-    @Override
-    public int read() throws IOException {
-      if (--bytesRemaining < 0) {
-        if (!done) {
-          inputStream.skip(finalSkip);
-        }
-        done = true;
-        return -1;
-      }
-      return inputStream.read();
-    }
-  }
 }