diff options
Diffstat (limited to 'src/leveldb/doc')
| -rw-r--r-- | src/leveldb/doc/bench/db_bench_sqlite3.cc | 2 | ||||
| -rw-r--r-- | src/leveldb/doc/index.html | 8 | ||||
| -rw-r--r-- | src/leveldb/doc/log_format.txt | 4 | ||||
| -rw-r--r-- | src/leveldb/doc/table_format.txt | 12 |
4 files changed, 14 insertions, 12 deletions
diff --git a/src/leveldb/doc/bench/db_bench_sqlite3.cc b/src/leveldb/doc/bench/db_bench_sqlite3.cc index 256793a9db..e63aaa8dcc 100644 --- a/src/leveldb/doc/bench/db_bench_sqlite3.cc +++ b/src/leveldb/doc/bench/db_bench_sqlite3.cc @@ -618,7 +618,7 @@ class Benchmark { ErrorCheck(status); // Execute read statement - while ((status = sqlite3_step(read_stmt)) == SQLITE_ROW); + while ((status = sqlite3_step(read_stmt)) == SQLITE_ROW) {} StepErrorCheck(status); // Reset SQLite statement for another use diff --git a/src/leveldb/doc/index.html b/src/leveldb/doc/index.html index 521d2baf41..3ed0ed9d9e 100644 --- a/src/leveldb/doc/index.html +++ b/src/leveldb/doc/index.html @@ -408,7 +408,7 @@ The optional <code>FilterPolicy</code> mechanism can be used to reduce the number of disk reads substantially. <pre> leveldb::Options options; - options.filter_policy = NewBloomFilter(10); + options.filter_policy = NewBloomFilterPolicy(10); leveldb::DB* db; leveldb::DB::Open(options, "/tmp/testdb", &db); ... use the database ... @@ -420,7 +420,7 @@ The preceding code associates a based filtering policy with the database. Bloom filter based filtering relies on keeping some number of bits of data in memory per key (in this case 10 bits per key since that is the argument we passed -to NewBloomFilter). This filter will reduce the number of unnecessary +to NewBloomFilterPolicy). This filter will reduce the number of unnecessary disk reads needed for <code>Get()</code> calls by a factor of approximately a 100. Increasing the bits per key will lead to a larger reduction at the cost of more memory usage. We recommend that @@ -430,7 +430,7 @@ lot of random reads set a filter policy. If you are using a custom comparator, you should ensure that the filter policy you are using is compatible with your comparator. For example, consider a comparator that ignores trailing spaces when comparing keys. -<code>NewBloomFilter</code> must not be used with such a comparator. +<code>NewBloomFilterPolicy</code> must not be used with such a comparator. Instead, the application should provide a custom filter policy that also ignores trailing spaces. For example: <pre> @@ -438,7 +438,7 @@ also ignores trailing spaces. For example: private: FilterPolicy* builtin_policy_; public: - CustomFilterPolicy() : builtin_policy_(NewBloomFilter(10)) { } + CustomFilterPolicy() : builtin_policy_(NewBloomFilterPolicy(10)) { } ~CustomFilterPolicy() { delete builtin_policy_; } const char* Name() const { return "IgnoreTrailingSpacesFilter"; } diff --git a/src/leveldb/doc/log_format.txt b/src/leveldb/doc/log_format.txt index 3a0414b65a..5228f624de 100644 --- a/src/leveldb/doc/log_format.txt +++ b/src/leveldb/doc/log_format.txt @@ -4,8 +4,8 @@ exception is that the tail of the file may contain a partial block. Each block consists of a sequence of records: block := record* trailer? record := - checksum: uint32 // crc32c of type and data[] - length: uint16 + checksum: uint32 // crc32c of type and data[] ; little-endian + length: uint16 // little-endian type: uint8 // One of FULL, FIRST, MIDDLE, LAST data: uint8[length] diff --git a/src/leveldb/doc/table_format.txt b/src/leveldb/doc/table_format.txt index d0f3065ed0..ca8f9b4460 100644 --- a/src/leveldb/doc/table_format.txt +++ b/src/leveldb/doc/table_format.txt @@ -18,6 +18,8 @@ The file contains internal pointers. Each such pointer is called a BlockHandle and contains the following information: offset: varint64 size: varint64 +See https://developers.google.com/protocol-buffers/docs/encoding#varints +for an explanation of varint64 format. (1) The sequence of key/value pairs in the file are stored in sorted order and partitioned into a sequence of data blocks. These blocks @@ -41,11 +43,11 @@ BlockHandle for the data block. (6) At the very end of the file is a fixed length footer that contains the BlockHandle of the metaindex and index blocks as well as a magic number. - metaindex_handle: char[p]; // Block handle for metaindex - index_handle: char[q]; // Block handle for index - padding: char[40-p-q]; // 0 bytes to make fixed length - // (40==2*BlockHandle::kMaxEncodedLength) - magic: fixed64; // == 0xdb4775248b80fb57 + metaindex_handle: char[p]; // Block handle for metaindex + index_handle: char[q]; // Block handle for index + padding: char[40-p-q]; // zeroed bytes to make fixed length + // (40==2*BlockHandle::kMaxEncodedLength) + magic: fixed64; // == 0xdb4775248b80fb57 (little-endian) "filter" Meta Block ------------------- |