BigArrayImpl.removeBeforeIndex throws IndexOutOfBoundsException when called with headIndex

[imjorge]

Calling BigArrayImpl.removeBeforeIndex with the headIndex seems a valid use case to remove all elements from the big array, even tough you could achieve the same thing with a call to removeAll.

The following code:

    public static void main(String[] args) throws Exception {
        String basePath = new File(System.getProperty("java.io.tmpdir"), "test").getPath();
        IBigArray bigArray = new BigArrayImpl(basePath, "demo");
        try {
            // append some items into the array
            for(int i = 0; i < 2; ++i) {
              bigArray.append(String.valueOf(i).getBytes());
            }

            // get current size of the array
            System.out.println("size: " + bigArray.size());

            for (long index = bigArray.getTailIndex(); index != bigArray.getHeadIndex(); index = (index == Long.MAX_VALUE ? 0 : index + 1)) {
                String item = new String(bigArray.get(index));
                System.out.println("item[" + index + "]=" + item);
            }

            bigArray.removeBeforeIndex(bigArray.getHeadIndex());

            System.out.println("size: " + bigArray.size());

            for (long index = bigArray.getTailIndex(); index != bigArray.getHeadIndex(); index = (index == Long.MAX_VALUE ? 0 : index + 1)) {
                String item = new String(bigArray.get(index));
                System.out.println("item[" + index + "]=" + item);
            }

            // empty the big array
            bigArray.removeAll();
        } finally {
            bigArray.close();
        }
    }

outputs to the console:

size: 2
item[0]=0
item[1]=1
Exception in thread "main" java.lang.IndexOutOfBoundsException
    at com.leansoft.bigqueue.BigArrayImpl.validateIndex(BigArrayImpl.java:458)
    at com.leansoft.bigqueue.BigArrayImpl.removeBeforeIndex(BigArrayImpl.java:198)
    at com.jorge.test.BigArrayMain.main(BigArrayMain.java:27)

Perhaps removeBeforeIndex should be changed to something like:

    @Override
    public void removeBeforeIndex(long index) throws IOException {
        try {
            arrayWriteLock.lock();

            if (index == arrayHeadIndex.get()) {
                this.indexPageFactory.deleteAllPages();
                this.dataPageFactory.deleteAllPages();
                this.metaPageFactory.deleteAllPages();

                this.commonInit();
            } else {
                validateIndex(index);

                long indexPageIndex = Calculator.div(index, INDEX_ITEMS_PER_PAGE_BITS);

                ByteBuffer indexItemBuffer = this.getIndexItemBuffer(index);
                long dataPageIndex = indexItemBuffer.getLong();

                long toRemoveIndexPageTimestamp = this.indexPageFactory.getPageFileLastModifiedTime(indexPageIndex);
                long toRemoveDataPageItemstamp = this.dataPageFactory.getPageFileLastModifiedTime(dataPageIndex);

                if (toRemoveIndexPageTimestamp > 0L) { 
                    this.indexPageFactory.deletePagesBefore(toRemoveIndexPageTimestamp);
                }
                if (toRemoveDataPageItemstamp > 0L) {
                    this.dataPageFactory.deletePagesBefore(toRemoveDataPageItemstamp);
                }

                // advance the tail to index
                this.arrayTailIndex.set(index);
            }
        } finally {
            arrayWriteLock.unlock();
        }
    }