bool InnerNode::write_msgbuf(BlockWriter& writer, MsgBuf *mb, Slice buffer)
{
if (tree_->compressor_) {
// 1. write to buffer
Block block(buffer, 0, 0);
BlockWriter wr(&block);
if (!mb->write_to(wr)) return false;
// 2. compress
assert(tree_->compressor_->max_compressed_length(block.size()) <=
writer.remain());
size_t compressed_length;
if (!tree_->compressor_->compress(buffer.data(), block.size(),
writer.addr(), &compressed_length)) {
LOG_ERROR("compress msgbuf error, nid " << nid_);
return false;
}
// 3. skip
writer.skip(compressed_length);
return true;
} else {
return mb->write_to(writer);
}
}
bool LeafNode::write_bucket(BlockWriter& writer, RecordBucket *bucket, Slice buffer)
{
if (tree_->compressor_) {
// 1. write to buffer
Block block(buffer, 0, 0);
BlockWriter wr(&block);
if (!write_bucket(wr, bucket)) return false;
// 2. compress
assert(tree_->compressor_->max_compressed_length(block.size()) <=
writer.remain());
size_t compressed_length;
if (!tree_->compressor_->compress(buffer.data(), block.size(),
writer.addr(), &compressed_length)) {
LOG_ERROR("compress msgbuf error, nid " << nid_);
return false;
}
// 3. skip
writer.skip(compressed_length);
return true;
} else {
return write_bucket(writer, bucket);
}
}
bool LeafNode::write_to(BlockWriter& writer, size_t& skeleton_size)
{
assert(status_ == kNew || status_ == kFullLoaded);
size_t skeleton_pos = writer.pos();
skeleton_size = 8 + 8 + buckets_info_size_;
if (!writer.skip(skeleton_size)) return false;
Slice buffer;
if (tree_->compressor_) {
size_t buffer_length = 0;
for (size_t i = 0; i < records_.buckets_number(); i++) {
if (buffer_length < records_.bucket_length(i)) {
buffer_length = records_.bucket_length(i);
}
}
buffer = Slice::alloc(buffer_length);
}
assert(records_.buckets_number() == buckets_info_.size());
for (size_t i = 0; i < records_.buckets_number(); i++ ) {
RecordBucket* bucket = records_.bucket(i);
buckets_info_[i].offset = writer.pos();
if (!write_bucket(writer, bucket, buffer)) {
if (buffer.size()) {
buffer.destroy();
}
return false;
}
buckets_info_[i].length = writer.pos() - buckets_info_[i].offset;
buckets_info_[i].uncompressed_length = records_.bucket_length(i);
}
size_t last_pos = writer.pos();
if (buffer.size()) {
buffer.destroy();
}
writer.seek(skeleton_pos);
if (!writer.writeUInt64(left_sibling_)) return false;
if (!writer.writeUInt64(right_sibling_)) return false;
if (!write_buckets_info(writer)) {
LOG_ERROR("write buckets info error, nid " << nid_);
return false;
}
writer.seek(last_pos);
return true;
}
bool InnerNode::write_to(BlockWriter& writer, size_t& skeleton_size)
{
// get length of skeleton and reserve space for skeleton
size_t skeleton_offset = writer.pos();
size_t skeleton_length = 1 + 4 + 8 + 4 + 4 + 4;
for (size_t i = 0; i < pivots_.size(); i++) {
skeleton_length += pivot_size(pivots_[i].key);
}
if (!writer.skip(skeleton_length)) return false;
// prepare buffer if compression is enabled
Slice buffer;
if (tree_->compressor_) {
// get buffer length to serialize msgbuf
size_t buffer_length = first_msgbuf_->size();
for (size_t i = 0; i < pivots_.size(); i++) {
if (pivots_[i].msgbuf->size() > buffer_length)
buffer_length = pivots_[i].msgbuf->size();
}
buffer = Slice::alloc(buffer_length);
}
// write the first msgbuf
first_msgbuf_offset_ = writer.pos();
if (!write_msgbuf(writer, first_msgbuf_, buffer)) return false;
first_msgbuf_length_ = writer.pos() - first_msgbuf_offset_;
first_msgbuf_uncompressed_length_ = first_msgbuf_->size();
// write rest msgbufs
for (size_t i = 0; i < pivots_.size(); i++) {
pivots_[i].offset = writer.pos();
if (!write_msgbuf(writer, pivots_[i].msgbuf, buffer)) return false;
pivots_[i].length = writer.pos() - pivots_[i].offset;
pivots_[i].uncompressed_length = pivots_[i].msgbuf->size();
}
if (buffer.size()) {
buffer.destroy();
}
size_t last_offset = writer.pos();
// seek to the head and write index
writer.seek(skeleton_offset);
if (!writer.writeBool(bottom_)) return false;
if (!writer.writeUInt32(pivots_.size())) return false;
if (!writer.writeUInt64(first_child_)) return false;
if (!writer.writeUInt32(first_msgbuf_offset_)) return false;
if (!writer.writeUInt32(first_msgbuf_length_)) return false;
if (!writer.writeUInt32(first_msgbuf_uncompressed_length_)) return false;
for (size_t i = 0; i < pivots_.size(); i++) {
if (!writer.writeSlice(pivots_[i].key)) return false;
if (!writer.writeUInt64(pivots_[i].child)) return false;
if (!writer.writeUInt32(pivots_[i].offset)) return false;
if (!writer.writeUInt32(pivots_[i].length)) return false;
if (!writer.writeUInt32(pivots_[i].uncompressed_length)) return false;
}
writer.seek(last_offset);
skeleton_size = skeleton_length;
return true;
}