public boolean putKey(final String key, final long phyOffset, final long storeTimestamp) {
        if (this.indexHeader.getIndexCount() < this.indexNum) {
            int keyHash = indexKeyHashMethod(key);
            int slotPos = keyHash % this.hashSlotNum;
            int absSlotPos = IndexHeader.INDEX_HEADER_SIZE + slotPos * hashSlotSize;

            try {

                int slotValue = this.mappedByteBuffer.getInt(absSlotPos);
                if (slotValue <= invalidIndex || slotValue > this.indexHeader.getIndexCount()) {
                    slotValue = invalidIndex;
                }

                long timeDiff = storeTimestamp - this.indexHeader.getBeginTimestamp();

                timeDiff = timeDiff / 1000;

                if (this.indexHeader.getBeginTimestamp() <= 0) {
                    timeDiff = 0;
                } else if (timeDiff > Integer.MAX_VALUE) {
                    timeDiff = Integer.MAX_VALUE;
                } else if (timeDiff < 0) {
                    timeDiff = 0;
                }

                int absIndexPos =
                    IndexHeader.INDEX_HEADER_SIZE + this.hashSlotNum * hashSlotSize
                        + this.indexHeader.getIndexCount() * indexSize;

                this.mappedByteBuffer.putInt(absIndexPos, keyHash);
                this.mappedByteBuffer.putLong(absIndexPos + 4, phyOffset);
                this.mappedByteBuffer.putInt(absIndexPos + 4 + 8, (int) timeDiff);
                this.mappedByteBuffer.putInt(absIndexPos + 4 + 8 + 4, slotValue);

                this.mappedByteBuffer.putInt(absSlotPos, this.indexHeader.getIndexCount());

                if (this.indexHeader.getIndexCount() <= 1) {
                    this.indexHeader.setBeginPhyOffset(phyOffset);
                    this.indexHeader.setBeginTimestamp(storeTimestamp);
                }

                if (invalidIndex == slotValue) {
                    this.indexHeader.incHashSlotCount();
                }
                this.indexHeader.incIndexCount();
                this.indexHeader.setEndPhyOffset(phyOffset);
                this.indexHeader.setEndTimestamp(storeTimestamp);

                return true;
            } catch (Exception e) {
                log.error("putKey exception, Key: " + key + " KeyHashCode: " + key.hashCode(), e);
            }
        } else {
            log.warn("Over index file capacity: index count = " + this.indexHeader.getIndexCount()
                + "; index max num = " + this.indexNum);
        }

        return false;
    }
@Test
    public void testPutKey() throws Exception {
        IndexFile indexFile = new IndexFile("100", HASH_SLOT_NUM, INDEX_NUM, 0, 0);
        for (long i = 0; i < (INDEX_NUM - 1); i++) {
            boolean putResult = indexFile.putKey(Long.toString(i), i, System.currentTimeMillis());
            assertThat(putResult).isTrue();
        }

        // put over index file capacity.
        boolean putResult = indexFile.putKey(Long.toString(400), 400, System.currentTimeMillis());
        assertThat(putResult).isFalse();
        indexFile.destroy(0);
        File file = new File("100");
        UtilAll.deleteFile(file);
    }