com.google.javascript.jscomp.FileInstrumentationData.java Source code

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Here is the source code for com.google.javascript.jscomp.FileInstrumentationData.java

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/*
 * Copyright 2009 The Closure Compiler Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.javascript.jscomp;

import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
import com.google.common.primitives.UnsignedBytes;

import java.util.BitSet;

/**
 * Holds instrumentation details related to a file, namely, the filename,
 * the array name used in instrumentation, and the lines which were
 * instrumented (in encoded form).
 * @author praveenk@google.com (Praveen Kumashi)
 */
class FileInstrumentationData {
    private final BitSet instrumentedBits;
    private final String arrayName;
    private final String fileName;

    FileInstrumentationData(String fileName, String arrayName) {
        this.fileName = fileName;
        this.arrayName = arrayName;
        instrumentedBits = new BitSet();
    }

    String getArrayName() {
        return arrayName;
    }

    String getFileName() {
        return fileName;
    }

    /**
     * Returns a byte-wise hex string representation of the BitField from
     * MSB (Most Significant Byte) to LSB (Least Significant Byte).
     * Eg. Single byte: a setting of "0001 1111", returns "1f"
     * Eg. Multiple bytes: a setting of "0000 0010 0001 1111", returns "1f02"
     *
     * @return string representation of bits set
     */
    String getInstrumentedLinesAsHexString() {
        StringBuilder builder = new StringBuilder();

        // Build the hex string.
        for (byte byteEntry : instrumentedBits.toByteArray()) {
            // Java bytes are signed, but we want the value as if it were unsigned.
            int value = UnsignedBytes.toInt(byteEntry);
            String hexString = Integer.toHexString(value);

            // Pad string to be two characters (if it isn't already).
            hexString = Strings.padStart(hexString, 2, '0');

            builder.append(hexString);
        }

        return builder.toString();
    }

    /**
     * Mark given 1-based line number as instrumented. Zero, Negative numbers
     * are not allowed.
     * @param lineNumber the line number which was instrumented
     */
    void setLineAsInstrumented(int lineNumber) {
        Preconditions.checkArgument(lineNumber > 0, "Expected non-zero positive integer as line " + "number.");

        // Map the 1-based line number to 0-based bit position
        instrumentedBits.set(lineNumber - 1);
    }
}