Err:  syscall.EISDIR,
		}
	}

	return &LockedFile{f}, nil
}

// TryLockedOpenFile - tries a new write lock, functionality
// it is similar to LockedOpenFile with with syscall.LOCK_EX
// mode but along with syscall.LOCK_NB such that the function
// doesn't wait forever but instead returns if it cannot
// acquire a write lock.
func TryLockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {

          #!/usr/local/bin/runbld --redirect-stderr
          set -euo pipefail
          export google_storage_service_account=$(pwd)/gcs_service_account.json

          set +x
          VAULT_TOKEN=$(vault write -field=token auth/approle/login role_id=$VAULT_ROLE_ID secret_id=$VAULT_SECRET_ID)
          export VAULT_TOKEN

        for (final String dialect : this.dialects) {
            bos.write(0x02);
            try {
                bos.write(Strings.getASCIIBytes(dialect));
            } catch (final IOException e) {
                throw new RuntimeCIFSException(e);
            }
            bos.write(0x0);
        }

        System.arraycopy(bos.toByteArray(), 0, dst, dstIndex, bos.size());

 */
@Deprecated(since = "4.0.0")
public interface ToolchainsWriter {

    /**
     * Writes the supplied toolchains to the specified character writer. The writer will be automatically closed before
     * the method returns.
     *
     * @param output The writer to serialize the toolchains to, must not be {@code null}.

        this.srcHashCode = 0;
    }

    int writeWireFormat(final byte[] dst, final int dstIndex) {
        // write 0x20 in first byte
        dst[dstIndex] = 0x20;

        // write name
        try {
            final byte tmp[] = name.getBytes(Name.OEM_ENCODING);
            int i;
            for (i = 0; i < tmp.length; i++) {

// EncodeMsg implements msgp.Encodable
func (z *dataUsageCache) EncodeMsg(en *msgp.Writer) (err error) {
	// map header, size 2
	// write "Info"
	err = en.Append(0x82, 0xa4, 0x49, 0x6e, 0x66, 0x6f)
	if err != nil {
		return
	}
	err = z.Info.EncodeMsg(en)
	if err != nil {
		err = msgp.WrapError(err, "Info")
		return
	}
	// write "Cache"
	err = en.Append(0xa5, 0x43, 0x61, 0x63, 0x68, 0x65)
	if err != nil {

	return n, nil
}

func (f *testFile) Write(b []byte) (int, error) {
	if len(b) == 0 {
		return 0, nil
	}
	if len(f.ops) == 0 {
		return 0, errors.New("unexpected Write operation")
	}
	s, ok := f.ops[0].(string)
	if !ok {
		return 0, errors.New("unexpected Write operation")
	}

	if !strings.HasPrefix(s, string(b)) {
		return 0, testError{fmt.Errorf("got Write(%q), want Write(%q)", b, s)}
	}
	if len(s) > len(b) {

            baos.write(content.length);
        } else {
            baos.write(0x82); // length of length = 2
            baos.write((content.length >> 8) & 0xFF);
            baos.write(content.length & 0xFF);
        }

        baos.write(content);
        return baos.toByteArray();
    }

```
cat ${HADOOP_CONF_DIR}/core-site.xml | kv-pairify | grep "mapred"

mapred.maxthreads.generate.mapoutput=2 # Num threads to write map outputs
mapred.maxthreads.partition.closer=0 # Asynchronous map flushers
mapreduce.fileoutputcommitter.algorithm.version=2 # Use the latest committer version
mapreduce.job.reduce.slowstart.completedmaps=0.99 # 99% map, then reduce

            buf[index - i] = value;
            i--;
        }
        return n;
    }

    /**
     * Writes an octet array to the buffer.
     *
     * @param b the byte array to write
     * @param i the starting index in the array
     * @param l the number of bytes to write
     */
    public void writeOctetArray(final byte[] b, final int i, final int l) {
        System.arraycopy(b, i, buf, index, l);