--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+
+#include "LevelDBStore.h"
+#include <set>
+#include <map>
+#include <string>
+#include <tr1/memory>
+#include "leveldb/include/leveldb/db.h"
+#include "leveldb/include/leveldb/write_batch.h"
+#include "leveldb/include/leveldb/slice.h"
+#include <errno.h>
+using std::string;
+
+int LevelDBStore::init(ostream &out)
+{
+ leveldb::Options options;
+ options.create_if_missing = true;
+ leveldb::DB *_db;
+ leveldb::Status status = leveldb::DB::Open(options, path, &_db);
+ db.reset(_db);
+ if (!status.ok()) {
+ out << status.ToString() << std::endl;
+ return -EINVAL;
+ } else
+ return 0;
+}
+
+void LevelDBStore::LevelDBTransactionImpl::set(
+ const string &prefix,
+ const std::map<string, bufferlist> &to_set)
+{
+ for (std::map<string, bufferlist>::const_iterator i = to_set.begin();
+ i != to_set.end();
+ ++i) {
+ buffers.push_back(i->second);
+ buffers.rbegin()->rebuild();
+ bufferlist &bl = *(buffers.rbegin());
+ string key = combine_strings(prefix, i->first);
+ keys.push_back(key);
+ bat.Delete(leveldb::Slice(*(keys.rbegin())));
+ bat.Put(leveldb::Slice(*(keys.rbegin())),
+ leveldb::Slice(bl.c_str(), bl.length()));
+ }
+}
+void LevelDBStore::LevelDBTransactionImpl::rmkeys(const string &prefix,
+ const std::set<string> &to_rm)
+{
+ for (std::set<string>::const_iterator i = to_rm.begin();
+ i != to_rm.end();
+ ++i) {
+ string key = combine_strings(prefix, *i);
+ keys.push_back(key);
+ bat.Delete(leveldb::Slice(*(keys.rbegin())));
+ }
+}
+
+void LevelDBStore::LevelDBTransactionImpl::rmkeys_by_prefix(const string &prefix)
+{
+ KeyValueDB::Iterator it = db->get_iterator(prefix);
+ for (it->seek_to_first();
+ it->valid();
+ it->next()) {
+ string key = combine_strings(prefix, it->key());
+ keys.push_back(key);
+ bat.Delete(*(keys.rbegin()));
+ }
+}
+
+int LevelDBStore::get(
+ const string &prefix,
+ const std::set<string> &keys,
+ std::map<string, bufferlist> *out)
+{
+ KeyValueDB::Iterator it = get_iterator(prefix);
+ for (std::set<string>::const_iterator i = keys.begin();
+ i != keys.end();
+ ++i) {
+ it->lower_bound(*i);
+ if (it->valid() && it->key() == *i) {
+ out->insert(make_pair(*i, it->value()));
+ } else if (!it->valid())
+ break;
+ }
+ return 0;
+}
+
+string LevelDBStore::combine_strings(const string &prefix, const string &value)
+{
+ string out = prefix;
+ out.push_back(0);
+ out.append(value);
+ return out;
+}
+
+bufferlist LevelDBStore::to_bufferlist(leveldb::Slice in)
+{
+ bufferlist bl;
+ bl.append(bufferptr(in.data(), in.size()));
+ return bl;
+}
+
+int LevelDBStore::split_key(leveldb::Slice in, string *prefix, string *key)
+{
+ string in_prefix = in.ToString();
+ size_t prefix_len = in_prefix.find('\0');
+ if (prefix_len >= in_prefix.size())
+ return -EINVAL;
+
+ if (prefix)
+ *prefix = string(in_prefix, 0, prefix_len);
+ if (key)
+ *key= string(in_prefix, prefix_len + 1);
+ return 0;
+}
--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+#ifndef LEVEL_DB_STORE_H
+#define LEVEL_DB_STORE_H
+
+#include "include/buffer.h"
+#include "KeyValueDB.h"
+#include <set>
+#include <map>
+#include <string>
+#include <tr1/memory>
+#include <boost/scoped_ptr.hpp>
+#include "leveldb/include/leveldb/db.h"
+#include "leveldb/include/leveldb/write_batch.h"
+#include "leveldb/include/leveldb/slice.h"
+
+/**
+ * Uses LevelDB to implement the KeyValueDB interface
+ */
+class LevelDBStore : public KeyValueDB {
+ string path;
+ boost::scoped_ptr<leveldb::DB> db;
+public:
+ LevelDBStore(const string &path) : path(path) {}
+
+ /// Opens underlying db
+ int init(ostream &out);
+
+ class LevelDBTransactionImpl : public KeyValueDB::TransactionImpl {
+ public:
+ leveldb::WriteBatch bat;
+ list<bufferlist> buffers;
+ list<string> keys;
+ LevelDBStore *db;
+
+ LevelDBTransactionImpl(LevelDBStore *db) : db(db) {}
+ void set(
+ const string &prefix,
+ const std::map<string, bufferlist> &to_set
+ );
+ void rmkeys(
+ const string &prefix,
+ const std::set<string> &keys
+ );
+ void rmkeys_by_prefix(
+ const string &prefix
+ );
+ };
+
+ KeyValueDB::Transaction get_transaction() {
+ return std::tr1::shared_ptr< LevelDBTransactionImpl >(
+ new LevelDBTransactionImpl(this));
+ }
+
+ int submit_transaction(KeyValueDB::Transaction t) {
+ LevelDBTransactionImpl * _t =
+ static_cast<LevelDBTransactionImpl *>(t.get());
+ leveldb::Status s = db->Write(leveldb::WriteOptions(), &(_t->bat));
+ return s.ok() ? 0 : -1;
+ }
+
+ int get(
+ const string &prefix,
+ const std::set<string> &key,
+ std::map<string, bufferlist> *out
+ );
+
+ class LevelDBIteratorImpl : public KeyValueDB::IteratorImpl {
+ boost::scoped_ptr<leveldb::Iterator> dbiter;
+ const string prefix;
+ public:
+ LevelDBIteratorImpl(leveldb::Iterator *iter, const string &prefix) :
+ dbiter(iter), prefix(prefix) {}
+ int seek_to_first() {
+ leveldb::Slice slice_prefix(prefix);
+ dbiter->Seek(slice_prefix);
+ return dbiter->status().ok() ? 0 : -1;
+ }
+ int seek_to_last() {
+ string limit = past_prefix(prefix);
+ leveldb::Slice slice_limit(limit);
+ dbiter->Seek(slice_limit);
+ if (!dbiter->Valid()) {
+ dbiter->SeekToLast();
+ } else {
+ dbiter->Prev();
+ }
+ return dbiter->status().ok() ? 0 : -1;
+ }
+ int upper_bound(const string &after) {
+ lower_bound(after);
+ if (valid() && key() == after)
+ next();
+ return dbiter->status().ok() ? 0 : -1;
+ }
+ int lower_bound(const string &to) {
+ string bound = combine_strings(prefix, to);
+ leveldb::Slice slice_bound(bound);
+ dbiter->Seek(slice_bound);
+ return dbiter->status().ok() ? 0 : -1;
+ }
+ bool valid() {
+ return dbiter->Valid() && in_prefix(prefix, dbiter->key());
+ }
+ int next() {
+ if (valid())
+ dbiter->Next();
+ return dbiter->status().ok() ? 0 : -1;
+ }
+ int prev() {
+ if (valid())
+ dbiter->Prev();
+ return dbiter->status().ok() ? 0 : -1;
+ }
+ string key() {
+ string out_key;
+ split_key(dbiter->key(), 0, &out_key);
+ return out_key;
+ }
+ bufferlist value() {
+ return to_bufferlist(dbiter->value());
+ }
+ int status() {
+ return dbiter->status().ok() ? 0 : -1;
+ }
+ };
+ Iterator get_iterator(const string &prefix) {
+ return std::tr1::shared_ptr<LevelDBIteratorImpl>(
+ new LevelDBIteratorImpl(
+ db->NewIterator(leveldb::ReadOptions()),
+ prefix));
+ }
+
+
+ /// Utility
+ static string combine_strings(const string &prefix, const string &value);
+ static int split_key(leveldb::Slice in, string *prefix, string *key);
+ static bufferlist to_bufferlist(leveldb::Slice in);
+ static bool in_prefix(const string &prefix, leveldb::Slice key) {
+ return (key.compare(leveldb::Slice(past_prefix(prefix))) < 0) &&
+ (key.compare(leveldb::Slice(prefix)) > 0);
+ }
+ static string past_prefix(const string prefix) {
+ string limit = prefix;
+ limit.push_back(1);
+ return limit;
+ }
+};
+
+#endif
projects / ceph.git / commitdiff