LBRYCommunity/lbrycrd
1
0
Fork 0
Code Issues 29 Pull requests 1 Projects Releases 32 Packages Wiki Activity

Use fixed preallocation instead of costly GetSerializeSize

Browse source 
Dbwrapper used GetSerializeSize() to compute the size of the buffer
to preallocate. For some cases (specifically: CCoins) this requires
a costly compression call. Avoid this by just using fixed size
preallocations instead.
This commit is contained in:
Pieter Wuille 2016-10-28 19:12:39 -07:00
parent 25a211aa9e
commit d59a518466
1 changed files with 9 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
src/dbwrapper.h
View file

@ -17,6 +17,9 @@
#include <leveldb/db.h>
#include <leveldb/write_batch.h>
static const size_t DBWRAPPER_PREALLOC_KEY_SIZE = 64;
static const size_t DBWRAPPER_PREALLOC_VALUE_SIZE = 1024;
class dbwrapper_error : public std::runtime_error
{
public:
@ -60,12 +63,12 @@ public:
void Write(const K& key, const V& value)
{
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(GetSerializeSize(ssKey, key));
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
ssKey << key;
leveldb::Slice slKey(&ssKey[0], ssKey.size());
CDataStream ssValue(SER_DISK, CLIENT_VERSION);
ssValue.reserve(GetSerializeSize(ssValue, value));
ssValue.reserve(DBWRAPPER_PREALLOC_VALUE_SIZE);
ssValue << value;
ssValue.Xor(dbwrapper_private::GetObfuscateKey(parent));
leveldb::Slice slValue(&ssValue[0], ssValue.size());
@ -77,7 +80,7 @@ public:
void Erase(const K& key)
{
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(GetSerializeSize(ssKey, key));
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
ssKey << key;
leveldb::Slice slKey(&ssKey[0], ssKey.size());
@ -107,7 +110,7 @@ public:
template<typename K> void Seek(const K& key) {
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(GetSerializeSize(ssKey, key));
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
ssKey << key;
leveldb::Slice slKey(&ssKey[0], ssKey.size());
piter->Seek(slKey);
@ -200,7 +203,7 @@ public:
bool Read(const K& key, V& value) const
{
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(GetSerializeSize(ssKey, key));
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
ssKey << key;
leveldb::Slice slKey(&ssKey[0], ssKey.size());
@ -234,7 +237,7 @@ public:
bool Exists(const K& key) const
{
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(GetSerializeSize(ssKey, key));
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
ssKey << key;
leveldb::Slice slKey(&ssKey[0], ssKey.size());