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// Test NamespaceDetails::cappedTruncateAfter via "captrunc" command
//
// @tags: [
// # This test attempts to perform read operations on a capped collection after truncating
// # documents using the captrunc command. The former operations may be routed to a secondary in
// # the replica set, whereas the latter must be routed to the primary.
// assumes_read_preference_unchanged,
// requires_non_retryable_commands,
// requires_fastcount,
// requires_capped,
// ]
(function() {
var coll = db.capped6;
Random.setRandomSeed();
var maxDocuments = Random.randInt(400) + 100;
/**
* Check that documents in the collection are in order according to the value
* of a, which corresponds to the insert order. This is a check that the oldest
* document(s) is/are deleted when space is needed for the newest document. The
* check is performed in both forward and reverse directions.
*/
function checkOrder(i, valueArray) {
res = coll.find().sort({$natural: -1});
assert(res.hasNext(), "A");
var j = i;
while (res.hasNext()) {
assert.eq(valueArray[j--].a, res.next().a, "B");
}
res = coll.find().sort({$natural: 1});
assert(res.hasNext(), "C");
while (res.hasNext()) {
assert.eq(valueArray[++j].a, res.next().a, "D");
}
assert.eq(j, i, "E");
}
/*
* Prepare the values to insert and create the capped collection.
*/
function prepareCollection(shouldReverse) {
coll.drop();
assert.commandWorked(
db.createCollection("capped6", {capped: true, size: 1000, $nExtents: 11}));
var valueArray = new Array(maxDocuments);
var c = "";
for (i = 0; i < maxDocuments; ++i, c += "-") {
// The a values are strings of increasing length.
valueArray[i] = {a: c};
}
if (shouldReverse) {
valueArray.reverse();
}
return valueArray;
}
/**
* 1. When this function is called the first time, insert new documents until 'maxDocuments'
* number of documents have been inserted. Note that the collection may not have
* 'maxDocuments' number of documents since it is a capped collection.
* 2. Remove all but one documents via one or more "captrunc" requests.
* 3. For each subsequent call to this function, keep track of the removed documents using
* 'valueArrayIndexes' and re-insert the removed documents each time this function is
* called.
*/
function runCapTrunc(valueArray, valueArrayCurIndex, n, inc) {
// If n <= 0, no documents are removed by captrunc.
assert.gt(n, 0);
assert.gte(valueArray.length, maxDocuments);
for (var i = valueArrayCurIndex; i < maxDocuments; ++i) {
assert.writeOK(coll.insert(valueArray[i]));
}
count = coll.count();
// The index corresponding to the last document in the collection.
valueArrayCurIndex = maxDocuments - 1;
// Number of times to call "captrunc" so that (count - 1) documents are removed
// and at least 1 document is left in the array.
var iterations = Math.floor((count - 1) / (n + inc));
for (i = 0; i < iterations; ++i) {
assert.commandWorked(db.runCommand({captrunc: "capped6", n: n, inc: inc}));
count -= (n + inc);
valueArrayCurIndex -= (n + inc);
checkOrder(valueArrayCurIndex, valueArray);
}
// We return the index of the next document that should be inserted into the capped
// collection, which would be the document after valueArrayCurIndex.
return valueArrayCurIndex + 1;
}
function doTest(shouldReverse) {
var valueArray = prepareCollection(shouldReverse);
var valueArrayIndex = 0;
valueArrayIndex = runCapTrunc(valueArray, valueArrayIndex, 1, false);
valueArrayIndex = runCapTrunc(valueArray, valueArrayIndex, 1, true);
valueArrayIndex = runCapTrunc(valueArray, valueArrayIndex, 16, true);
valueArrayIndex = runCapTrunc(valueArray, valueArrayIndex, 16, false);
valueArrayIndex = runCapTrunc(valueArray, valueArrayIndex, maxDocuments - 2, true);
valueArrayIndex = runCapTrunc(valueArray, valueArrayIndex, maxDocuments - 2, false);
}
// Repeatedly add up to 'maxDocuments' documents and then truncate the newest
// documents. Newer documents take up more space than older documents.
doTest(false);
// Same test as above, but now the newer documents take less space than the
// older documents instead of more.
doTest(true);
})();
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