tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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stringbuffer-5.js (3085B)

      1 // |jit-test| --setpref=objectfuse_for_global=false
      2 
      3 // Don't use object fuses for this test because atomizing global constants
      4 // affects what we're testing.
      5 
      6 // Test structured cloning of StringBuffer references.
      7 
      8 gczeal(0);
      9 
     10 var strLatin1 = newString("abcdefghijklmnopqrstuvwxyz".repeat(10), {newStringBuffer: true});
     11 var strTwoByte = newString("abcdefghijklmnopqrstuvwx\u3210\u1234".repeat(10), {newStringBuffer: true});
     12 
     13 function checkRefCount(s, expected) {
     14    // stringRepresentation and the bufferRefCount field aren't available in
     15    // all builds.
     16    if (getBuildConfiguration("debug")) {
     17        var repr = JSON.parse(stringRepresentation(s));
     18        assertEq(repr.bufferRefCount, expected);
     19    }
     20 }
     21 
     22 function test() {
     23    checkRefCount(strLatin1, 1);
     24    checkRefCount(strTwoByte, 1);
     25 
     26    // With SameProcess, we should transfer the reference so the resulting buffer
     27    // should be relatively small. The buffer contains 120 bytes currently so use
     28    // 200 as a reasonable upper limit.
     29    var clonebufferSameProcess = serialize([strLatin1, strTwoByte, strLatin1, strTwoByte],
     30                                           [], {scope: "SameProcess"});
     31    assertEq(clonebufferSameProcess.arraybuffer.byteLength < 200, true);
     32 
     33    // JS string + 2 refs from clone buffer
     34    checkRefCount(strLatin1, 3);
     35    checkRefCount(strTwoByte, 3);
     36 
     37    // Test deserialization.
     38    var arr1 = deserialize(clonebufferSameProcess);
     39    assertEq(arr1.length, 4);
     40    assertEq(arr1[0], strLatin1);
     41    assertEq(arr1[1], strTwoByte);
     42    assertEq(arr1[2], strLatin1);
     43    assertEq(arr1[3], strTwoByte);
     44 
     45    // JS string + 2 refs from clone buffer + 2 refs from |arr|
     46    checkRefCount(strLatin1, 5);
     47    checkRefCount(strTwoByte, 5);
     48 
     49    // With DifferentProcess, the string contents are serialized so we have a
     50    // larger buffer.
     51    var clonebufferDifferentProcess = serialize([strLatin1, strTwoByte, strLatin1, strTwoByte],
     52                                                [], {scope: "DifferentProcess"});
     53    assertEq(clonebufferDifferentProcess.arraybuffer.byteLength > 500, true);
     54 
     55    // Test deserialization.
     56    var arr2 = deserialize(clonebufferDifferentProcess);
     57    assertEq(arr2.length, 4);
     58    assertEq(arr2[0], strLatin1);
     59    assertEq(arr2[1], strTwoByte);
     60    assertEq(arr2[2], strLatin1);
     61    assertEq(arr2[3], strTwoByte);
     62 
     63    // Unchanged from before.
     64    checkRefCount(strLatin1, 5);
     65    checkRefCount(strTwoByte, 5);
     66 }
     67 test();
     68 
     69 // Trigger GC. This should drop all references except for the JS strings.
     70 gc();
     71 finishBackgroundFree();
     72 checkRefCount(strLatin1, 1);
     73 checkRefCount(strTwoByte, 1);
     74 
     75 function testAtom() {
     76    var sourceLatin1 = "abcde".repeat(200);
     77    var reLatin1 = new RegExp(sourceLatin1);
     78 
     79    var sourceTwoByte = "abcd\u1234".repeat(200);
     80    var reTwoByte = new RegExp(sourceTwoByte);
     81 
     82    var clonebuffer = serialize([reLatin1, reTwoByte], [], {scope: "SameProcess"});
     83    var arr = deserialize(clonebuffer);
     84    assertEq(arr.length, 2);
     85    assertEq(arr[0].source, sourceLatin1);
     86    assertEq(arr[1].source, sourceTwoByte);
     87 }
     88 testAtom();