index: Implement lookup methods on block filter index.

This commit is contained in:
Jim Posen 2018-08-27 18:39:28 -07:00
parent 75a76e3619
commit b5e8200db7
2 changed files with 167 additions and 0 deletions

View file

@ -4,6 +4,7 @@
#include <map>
#include <dbwrapper.h>
#include <index/blockfilterindex.h>
#include <util/system.h>
#include <validation.h>
@ -143,6 +144,26 @@ bool BlockFilterIndex::CommitInternal(CDBBatch& batch)
return BaseIndex::CommitInternal(batch);
}
bool BlockFilterIndex::ReadFilterFromDisk(const FlatFilePos& pos, BlockFilter& filter) const
{
CAutoFile filein(m_filter_fileseq->Open(pos, true), SER_DISK, CLIENT_VERSION);
if (filein.IsNull()) {
return false;
}
uint256 block_hash;
std::vector<unsigned char> encoded_filter;
try {
filein >> block_hash >> encoded_filter;
filter = BlockFilter(GetFilterType(), block_hash, std::move(encoded_filter));
}
catch (const std::exception& e) {
return error("%s: Failed to deserialize block filter from disk: %s", __func__, e.what());
}
return true;
}
size_t BlockFilterIndex::WriteFilterToDisk(FlatFilePos& pos, const BlockFilter& filter)
{
assert(filter.GetFilterType() == GetFilterType());
@ -280,3 +301,134 @@ bool BlockFilterIndex::Rewind(const CBlockIndex* current_tip, const CBlockIndex*
return BaseIndex::Rewind(current_tip, new_tip);
}
static bool LookupOne(const CDBWrapper& db, const CBlockIndex* block_index, DBVal& result)
{
// First check if the result is stored under the height index and the value there matches the
// block hash. This should be the case if the block is on the active chain.
std::pair<uint256, DBVal> read_out;
if (!db.Read(DBHeightKey(block_index->nHeight), read_out)) {
return false;
}
if (read_out.first == block_index->GetBlockHash()) {
result = std::move(read_out.second);
return true;
}
// If value at the height index corresponds to an different block, the result will be stored in
// the hash index.
return db.Read(DBHashKey(block_index->GetBlockHash()), result);
}
static bool LookupRange(CDBWrapper& db, const std::string& index_name, int start_height,
const CBlockIndex* stop_index, std::vector<DBVal>& results)
{
if (start_height < 0) {
return error("%s: start height (%d) is negative", __func__, start_height);
}
if (start_height > stop_index->nHeight) {
return error("%s: start height (%d) is greater than stop height (%d)",
__func__, start_height, stop_index->nHeight);
}
size_t results_size = static_cast<size_t>(stop_index->nHeight - start_height + 1);
std::vector<std::pair<uint256, DBVal>> values(results_size);
DBHeightKey key(start_height);
std::unique_ptr<CDBIterator> db_it(db.NewIterator());
db_it->Seek(DBHeightKey(start_height));
for (int height = start_height; height <= stop_index->nHeight; ++height) {
if (!db_it->Valid() || !db_it->GetKey(key) || key.height != height) {
return false;
}
size_t i = static_cast<size_t>(height - start_height);
if (!db_it->GetValue(values[i])) {
return error("%s: unable to read value in %s at key (%c, %d)",
__func__, index_name, DB_BLOCK_HEIGHT, height);
}
db_it->Next();
}
results.resize(results_size);
// Iterate backwards through block indexes collecting results in order to access the block hash
// of each entry in case we need to look it up in the hash index.
for (const CBlockIndex* block_index = stop_index;
block_index && block_index->nHeight >= start_height;
block_index = block_index->pprev) {
uint256 block_hash = block_index->GetBlockHash();
size_t i = static_cast<size_t>(block_index->nHeight - start_height);
if (block_hash == values[i].first) {
results[i] = std::move(values[i].second);
continue;
}
if (!db.Read(DBHashKey(block_hash), results[i])) {
return error("%s: unable to read value in %s at key (%c, %s)",
__func__, index_name, DB_BLOCK_HASH, block_hash.ToString());
}
}
return true;
}
bool BlockFilterIndex::LookupFilter(const CBlockIndex* block_index, BlockFilter& filter_out) const
{
DBVal entry;
if (!LookupOne(*m_db, block_index, entry)) {
return false;
}
return ReadFilterFromDisk(entry.pos, filter_out);
}
bool BlockFilterIndex::LookupFilterHeader(const CBlockIndex* block_index, uint256& header_out) const
{
DBVal entry;
if (!LookupOne(*m_db, block_index, entry)) {
return false;
}
header_out = entry.header;
return true;
}
bool BlockFilterIndex::LookupFilterRange(int start_height, const CBlockIndex* stop_index,
std::vector<BlockFilter>& filters_out) const
{
std::vector<DBVal> entries;
if (!LookupRange(*m_db, m_name, start_height, stop_index, entries)) {
return false;
}
filters_out.resize(entries.size());
auto filter_pos_it = filters_out.begin();
for (const auto& entry : entries) {
if (!ReadFilterFromDisk(entry.pos, *filter_pos_it)) {
return false;
}
++filter_pos_it;
}
return true;
}
bool BlockFilterIndex::LookupFilterHashRange(int start_height, const CBlockIndex* stop_index,
std::vector<uint256>& hashes_out) const
{
std::vector<DBVal> entries;
if (!LookupRange(*m_db, m_name, start_height, stop_index, entries)) {
return false;
}
hashes_out.clear();
hashes_out.reserve(entries.size());
for (const auto& entry : entries) {
hashes_out.push_back(entry.hash);
}
return true;
}

View file

@ -27,6 +27,7 @@ private:
FlatFilePos m_next_filter_pos;
std::unique_ptr<FlatFileSeq> m_filter_fileseq;
bool ReadFilterFromDisk(const FlatFilePos& pos, BlockFilter& filter) const;
size_t WriteFilterToDisk(FlatFilePos& pos, const BlockFilter& filter);
protected:
@ -48,6 +49,20 @@ public:
size_t n_cache_size, bool f_memory = false, bool f_wipe = false);
BlockFilterType GetFilterType() const { return m_filter_type; }
/** Get a single filter by block. */
bool LookupFilter(const CBlockIndex* block_index, BlockFilter& filter_out) const;
/** Get a single filter header by block. */
bool LookupFilterHeader(const CBlockIndex* block_index, uint256& header_out) const;
/** Get a range of filters between two heights on a chain. */
bool LookupFilterRange(int start_height, const CBlockIndex* stop_index,
std::vector<BlockFilter>& filters_out) const;
/** Get a range of filter hashes between two heights on a chain. */
bool LookupFilterHashRange(int start_height, const CBlockIndex* stop_index,
std::vector<uint256>& hashes_out) const;
};
#endif // BITCOIN_INDEX_BLOCKFILTERINDEX_H