Examples with MappedByteBuffer java.nio.MappedByteBuffer used on opensource projects

Example 91 with MappedByteBuffer

use of java.nio.MappedByteBuffer in project buck by facebook.

the class AbstractElfClearProgramHeadersStep method execute.

@Override
public StepExecutionResult execute(ExecutionContext context) throws IOException {
    try (FileChannel channel = FileChannel.open(getFilesystem().resolve(getPath()), StandardOpenOption.READ, StandardOpenOption.WRITE)) {
        MappedByteBuffer buffer = channel.map(READ_WRITE, 0, channel.size());
        Elf elf = new Elf(buffer);
        Preconditions.checkState(elf.header.e_phoff == (int) elf.header.e_phoff, "program headers are expected to be within 4GB of beginning of file");
        buffer.position((int) elf.header.e_phoff);
        for (int index = 0; index < elf.header.e_phnum * elf.header.e_phentsize; index++) {
            buffer.put((byte) 0);
        }
    }
    return StepExecutionResult.SUCCESS;
}

Example 92 with MappedByteBuffer

use of java.nio.MappedByteBuffer in project buck by facebook.

the class UnixArchiveTest method testReadingArchive.

@Test
public void testReadingArchive() throws IOException {
    Path path = tmp.resolve("test_archive.a");
    createArchiveAtPath(path);
    UnixArchive archive = new UnixArchive(FileChannel.open(path, StandardOpenOption.READ, StandardOpenOption.WRITE), new NulTerminatedCharsetDecoder(StandardCharsets.UTF_8.newDecoder()));
    assertThat(archive.getEntries().size(), equalTo(3));
    assertThat(archive.getEntries().get(0).getFileName(), equalToObject("__.SYMDEF SORTED"));
    assertThat(archive.getEntries().get(0).getFileModificationTimestamp(), equalTo(1463146035L));
    assertThat(archive.getEntries().get(0).getOwnerId(), equalTo(10727));
    assertThat(archive.getEntries().get(0).getGroupId(), equalTo(11706));
    assertThat(archive.getEntries().get(0).getFileMode(), equalTo(100644));
    assertThat(archive.getEntries().get(1).getFileName(), equalToObject("file1.txt"));
    assertThat(archive.getEntries().get(1).getFileModificationTimestamp(), equalTo(1463145840L));
    assertThat(archive.getEntries().get(1).getFileSize(), equalTo(16L));
    MappedByteBuffer buffer1 = archive.getMapForEntry(archive.getEntries().get(1));
    byte[] strBytes1 = new byte[(int) archive.getEntries().get(1).getFileSize()];
    buffer1.get(strBytes1, 0, (int) archive.getEntries().get(1).getFileSize());
    assertThat(new String(strBytes1), equalToObject("FILE1_CONTENTS\n\n"));
    assertThat(archive.getEntries().get(2).getFileName(), equalToObject("file2.txt"));
    assertThat(archive.getEntries().get(2).getFileModificationTimestamp(), equalTo(1463145848L));
    assertThat(archive.getEntries().get(2).getFileSize(), equalTo(32L));
    MappedByteBuffer buffer2 = archive.getMapForEntry(archive.getEntries().get(2));
    byte[] strBytes2 = new byte[(int) archive.getEntries().get(2).getFileSize()];
    buffer2.get(strBytes2, 0, (int) archive.getEntries().get(2).getFileSize());
    assertThat(new String(strBytes2), equalToObject("FILE2_CONTENTS_FILE2_CONTENTS\n\n\n"));
    archive.close();
}

Example 93 with MappedByteBuffer

use of java.nio.MappedByteBuffer in project buck by facebook.

the class UnixArchiveTest method testModifyingArchive.

@Test
public void testModifyingArchive() throws IOException {
    Path path = tmp.resolve("test_archive.a");
    createArchiveAtPath(path);
    UnixArchive archive = new UnixArchive(FileChannel.open(path, StandardOpenOption.READ, StandardOpenOption.WRITE), new NulTerminatedCharsetDecoder(StandardCharsets.UTF_8.newDecoder()));
    MappedByteBuffer buffer = archive.getMapForEntry(archive.getEntries().get(1));
    byte[] bytes = new byte[(int) archive.getEntries().get(1).getFileSize()];
    buffer.get(bytes, 0, (int) archive.getEntries().get(1).getFileSize());
    assertThat(new String(bytes), equalToObject("FILE1_CONTENTS\n\n"));
    buffer.position(0);
    buffer.put("NEW_CONTENTS!!!!".getBytes(Charsets.UTF_8));
    archive.close();
    String updatedContents = new String(Files.readAllBytes(path));
    assertThat(updatedContents, not(containsString("FILE1_CONTENTS")));
    assertThat(updatedContents, containsString("NEW_CONTENTS!!!!"));
}

Example 94 with MappedByteBuffer

use of java.nio.MappedByteBuffer in project buck by facebook.

the class ObjectPathsAbsolutifier method fixCompDirInStaticLibrary.

private void fixCompDirInStaticLibrary(Path destination) throws IOException {
    FileChannel channel = FileChannel.open(destination, StandardOpenOption.READ, StandardOpenOption.WRITE);
    ByteBuffer buffer = channel.map(FileChannel.MapMode.READ_WRITE, 0, channel.size());
    if (!UnixArchive.checkHeader(buffer)) {
        LOG.warn("Static library at %s has wrong header, skipping", destination);
        return;
    }
    UnixArchive archive = new UnixArchive(channel, nulTerminatedCharsetDecoder);
    for (UnixArchiveEntry archiveEntry : archive.getEntries()) {
        if (archiveEntry.getFileName().endsWith(".o")) {
            MappedByteBuffer map = archive.getMapForEntry(archiveEntry);
            CompDirReplacer replacer = new CompDirReplacer(map, nulTerminatedCharsetDecoder);
            replacer.replaceCompDir(oldCompDir, newCompDir);
        }
    }
    archive.close();
}

Example 95 with MappedByteBuffer

use of java.nio.MappedByteBuffer in project buck by facebook.

the class ElfClearProgramHeadersStepTest method test.

@Test
public void test() throws IOException {
    ProjectWorkspace workspace = TestDataHelper.createProjectWorkspaceForScenario(this, "elf_shared_lib", tmp);
    workspace.setUp();
    ElfClearProgramHeadersStep step = ElfClearProgramHeadersStep.of(new ProjectFilesystem(tmp.getRoot()), tmp.getRoot().getFileSystem().getPath("libfoo.so"));
    step.execute(TestExecutionContext.newInstance());
    // Verify that the program table section is empty.
    try (FileChannel channel = FileChannel.open(step.getFilesystem().resolve(step.getPath()), StandardOpenOption.READ)) {
        MappedByteBuffer buffer = channel.map(READ_ONLY, 0, channel.size());
        Elf elf = new Elf(buffer);
        // Program headers are at the beginning of the file, so truncating to `int` should be ok.
        buffer.position((int) elf.header.e_phoff);
        for (int index = 0; index < elf.header.e_phnum * elf.header.e_phentsize; index++) {
            assertThat((int) buffer.get(), Matchers.equalTo(0));
        }
    }
}