/**
* Writes the value and value length for non-first record.
*
* @param kv Key-value writer.
* @return The offset of the new record.
*/
private long writeValueAndLength(KvSource kv) throws SerDeException {
long valueOffset = writeBuffers.getWritePoint();
kv.writeValue(writeBuffers);
long tailOffset = writeBuffers.getWritePoint();
writeBuffers.writeVLong(tailOffset - valueOffset);
// LOG.info("Writing value at " + valueOffset + " length " + (tailOffset - valueOffset));
return tailOffset;
}
/**
* @param ref The ref.
* @return The offset to list record pointer; list record is created if it doesn't exist.
*/
private long createOrGetListRecord(long ref) {
if (Ref.hasList(ref)) {
// LOG.info("Found list record at " + writeBuffers.getReadPoint());
return writeBuffers.getReadPoint(); // Assumes we are here after key compare.
}
long firstTailOffset = Ref.getOffset(ref);
// LOG.info("First tail offset to create list record is " + firstTailOffset);
// Determine the length of storage for value and key lengths of the first record.
writeBuffers.setReadPoint(firstTailOffset);
writeBuffers.skipVLong();
writeBuffers.skipVLong();
int lengthsLength = (int) (writeBuffers.getReadPoint() - firstTailOffset);
// Create the list record, copy first record value/key lengths there.
writeBuffers.writeBytes(firstTailOffset, lengthsLength);
long lrPtrOffset = writeBuffers.getWritePoint();
// LOG.info("Creating list record: copying " + lengthsLength + ", lrPtrOffset " + lrPtrOffset);
// Reserve 5 bytes for writeValueRecord to fill. There might be junk there so null them.
writeBuffers.write(FIVE_ZEROES);
// Link the list record to the first element.
writeBuffers.writeFiveByteULong(firstTailOffset, lrPtrOffset - lengthsLength - firstTailOffset);
return lrPtrOffset;
}
public void put(KvSource kv, int keyHashCode) throws SerDeException {
if (resizeThreshold <= keysAssigned) {
expandAndRehash();
}
// Reserve 4 bytes for the hash (don't just reserve, there may be junk there)
writeBuffers.write(FOUR_ZEROES);
// Write key to buffer to compute hashcode and compare; if it's a new key, it will
// become part of the record; otherwise, we will just write over it later.
long keyOffset = writeBuffers.getWritePoint();
kv.writeKey(writeBuffers);
int keyLength = (int) (writeBuffers.getWritePoint() - keyOffset);
int hashCode = (keyHashCode == -1) ? writeBuffers.hashCode(keyOffset, keyLength) : keyHashCode;
int slot = findKeySlotToWrite(keyOffset, keyLength, hashCode);
// LOG.info("Write hash code is " + Integer.toBinaryString(hashCode) + " - " + slot);
long ref = refs[slot];
if (ref == 0) {
// This is a new key, keep writing the first record.
long tailOffset = writeFirstValueRecord(kv, keyOffset, keyLength, hashCode);
byte stateByte = kv.updateStateByte(null);
refs[slot] = Ref.makeFirstRef(tailOffset, stateByte, hashCode, startingHashBitCount);
++keysAssigned;
} else {
// This is not a new key; we'll overwrite the key and hash bytes - not needed anymore.
writeBuffers.setWritePoint(keyOffset - 4);
long lrPtrOffset = createOrGetListRecord(ref);
long tailOffset = writeValueAndLength(kv);
addRecordToList(lrPtrOffset, tailOffset);
byte oldStateByte = Ref.getStateByte(ref);
byte stateByte = kv.updateStateByte(oldStateByte);
if (oldStateByte != stateByte) {
ref = Ref.setStateByte(ref, stateByte);
}
refs[slot] = Ref.setListFlag(ref);
}
++numValues;
}
/**
* Writes first value and lengths to finish the first record after the key has been written.
*
* @param kv Key-value writer.
* @param keyOffset
* @param keyLength Key length (already written).
* @param hashCode
* @return The offset of the new record.
*/
private long writeFirstValueRecord(KvSource kv, long keyOffset, int keyLength, int hashCode)
throws SerDeException {
long valueOffset = writeBuffers.getWritePoint();
kv.writeValue(writeBuffers);
long tailOffset = writeBuffers.getWritePoint();
int valueLength = (int) (tailOffset - valueOffset);
// LOG.info("Writing value at " + valueOffset + " length " + valueLength);
// In an unlikely case of 0-length key and value for the very first entry, we want to tell
// this apart from an empty value. We'll just advance one byte; this byte will be lost.
if (tailOffset == 0) {
writeBuffers.reserve(1);
++tailOffset;
}
// LOG.info("First tail offset " + writeBuffers.getWritePoint());
writeBuffers.writeVLong(valueLength);
writeBuffers.writeVLong(keyLength);
long lengthsLength = writeBuffers.getWritePoint() - tailOffset;
if (lengthsLength < 5) { // Reserve space for potential future list
writeBuffers.reserve(5 - (int) lengthsLength);
}
// Finally write the hash code.
writeBuffers.writeInt(keyOffset - 4, hashCode);
return tailOffset;
}