fix some trifling points

This commit is contained in:
xiong-ang 2021-10-22 18:00:57 +08:00
parent c5d5174a66
commit d7da5d9d35

View File

@ -345,7 +345,7 @@ non-NULL, it is used to cache frequently used uncompressed block contents.
#include "leveldb/cache.h" #include "leveldb/cache.h"
leveldb::Options options; leveldb::Options options;
options.block_cache = leveldb::NewLRUCache(100 * 1048576); // 100MB cache options.block_cache = leveldb::NewLRUCache(100 * 1048576); // 100M cache capacity
leveldb::DB* db; leveldb::DB* db;
leveldb::DB::Open(options, name, &db); leveldb::DB::Open(options, name, &db);
... use the db ... ... use the db ...
@ -369,6 +369,7 @@ leveldb::Iterator* it = db->NewIterator(options);
for (it->SeekToFirst(); it->Valid(); it->Next()) { for (it->SeekToFirst(); it->Valid(); it->Next()) {
... ...
} }
delete it;
``` ```
### Key Layout ### Key Layout
@ -424,21 +425,21 @@ spaces. For example:
```c++ ```c++
class CustomFilterPolicy : public leveldb::FilterPolicy { class CustomFilterPolicy : public leveldb::FilterPolicy {
private: private:
FilterPolicy* builtin_policy_; leveldb::FilterPolicy* builtin_policy_;
public: public:
CustomFilterPolicy() : builtin_policy_(NewBloomFilterPolicy(10)) {} CustomFilterPolicy() : builtin_policy_(leveldb::NewBloomFilterPolicy(10)) {}
~CustomFilterPolicy() { delete builtin_policy_; } ~CustomFilterPolicy() { delete builtin_policy_; }
const char* Name() const { return "IgnoreTrailingSpacesFilter"; } const char* Name() const { return "IgnoreTrailingSpacesFilter"; }
void CreateFilter(const Slice* keys, int n, std::string* dst) const { void CreateFilter(const leveldb::Slice* keys, int n, std::string* dst) const {
// Use builtin bloom filter code after removing trailing spaces // Use builtin bloom filter code after removing trailing spaces
std::vector<Slice> trimmed(n); std::vector<leveldb::Slice> trimmed(n);
for (int i = 0; i < n; i++) { for (int i = 0; i < n; i++) {
trimmed[i] = RemoveTrailingSpaces(keys[i]); trimmed[i] = RemoveTrailingSpaces(keys[i]);
} }
return builtin_policy_->CreateFilter(trimmed.data(), n, dst); builtin_policy_->CreateFilter(trimmed.data(), n, dst);
} }
}; };
``` ```