stringbuffer-5.js - mozsearch

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// Test structured cloning of StringBuffer references.

gczeal(0);

var strLatin1 = newString("abcdefghijklmnopqrstuvwxyz".repeat(10), {newStringBuffer: true});

var strTwoByte = newString("abcdefghijklmnopqrstuvwx\u3210\u1234".repeat(10), {newStringBuffer: true});

function checkRefCount(s, expected) {

    // stringRepresentation and the bufferRefCount field aren't available in

    // all builds.

    if (getBuildConfiguration("debug")) {

        var repr = JSON.parse(stringRepresentation(s));

        assertEq(repr.bufferRefCount, expected);

function test() {

    checkRefCount(strLatin1, 1);

    checkRefCount(strTwoByte, 1);

    // With SameProcess, we should transfer the reference so the resulting buffer

    // should be relatively small. The buffer contains 120 bytes currently so use

    // 200 as a reasonable upper limit.

    var clonebufferSameProcess = serialize([strLatin1, strTwoByte, strLatin1, strTwoByte],

                                           [], {scope: "SameProcess"});

    assertEq(clonebufferSameProcess.arraybuffer.byteLength < 200, true);

    // JS string + 2 refs from clone buffer

    checkRefCount(strLatin1, 3);

    checkRefCount(strTwoByte, 3);

    // Test deserialization.

    var arr1 = deserialize(clonebufferSameProcess);

    assertEq(arr1.length, 4);

    assertEq(arr1[0], strLatin1);

    assertEq(arr1[1], strTwoByte);

    assertEq(arr1[2], strLatin1);

    assertEq(arr1[3], strTwoByte);

    // JS string + 2 refs from clone buffer + 2 refs from |arr|

    checkRefCount(strLatin1, 5);

    checkRefCount(strTwoByte, 5);

    // With DifferentProcess, the string contents are serialized so we have a

    // larger buffer.

    var clonebufferDifferentProcess = serialize([strLatin1, strTwoByte, strLatin1, strTwoByte],

                                                [], {scope: "DifferentProcess"});

    assertEq(clonebufferDifferentProcess.arraybuffer.byteLength > 500, true);

    // Test deserialization.

    var arr2 = deserialize(clonebufferDifferentProcess);

    assertEq(arr2.length, 4);

    assertEq(arr2[0], strLatin1);

    assertEq(arr2[1], strTwoByte);

    assertEq(arr2[2], strLatin1);

    assertEq(arr2[3], strTwoByte);

    // Unchanged from before.

    checkRefCount(strLatin1, 5);

    checkRefCount(strTwoByte, 5);

test();

// Trigger GC. This should drop all references except for the JS strings.

gc();

finishBackgroundFree();

checkRefCount(strLatin1, 1);

checkRefCount(strTwoByte, 1);

function testAtom() {

    var sourceLatin1 = "abcde".repeat(200);

    var reLatin1 = new RegExp(sourceLatin1);

    var sourceTwoByte = "abcd\u1234".repeat(200);

    var reTwoByte = new RegExp(sourceTwoByte);

    var clonebuffer = serialize([reLatin1, reTwoByte], [], {scope: "SameProcess"});

    var arr = deserialize(clonebuffer);

    assertEq(arr.length, 2);

    assertEq(arr[0].source, sourceLatin1);

    assertEq(arr[1].source, sourceTwoByte);

testAtom();