ldb to support --column_family option

Summary:
Add an option --column_family option, so that users can query or update specific column family.
Also add an create column family parameter to make unit test easier.
Still need to add unit tests.

Test Plan: Will add a test case in ldb python test.

Reviewers: yhchiang, rven, andrewkr, IslamAbdelRahman, kradhakrishnan, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53265

HISTORY.md

@@ -1,9 +1,11 @@
 # Rocksdb Change Log
-
 ## Unreleased
 ### Public API Changes
 * Add a new perf context level between kEnableCount and kEnableTime. Level 2 now doesn't include timers for mutexes.
 
+### New Features
+* ldb tool now supports operations to non-default column families.
+
 ## 4.4.0 (1/14/2016)
 ### Public API Changes
 * Change names in CompactionPri and add a new one.

include/rocksdb/ldb_tool.h

@@ -5,6 +5,8 @@
 #ifndef ROCKSDB_LITE
 #pragma once
 #include <string>
+#include <vector>
+#include "rocksdb/db.h"
 #include "rocksdb/options.h"
 
 namespace rocksdb {
@@ -28,8 +30,10 @@ struct LDBOptions {
 
 class LDBTool {
  public:
-  void Run(int argc, char** argv, Options db_options= Options(),
-           const LDBOptions& ldb_options = LDBOptions());
+  void Run(
+      int argc, char** argv, Options db_options = Options(),
+      const LDBOptions& ldb_options = LDBOptions(),
+      const std::vector<ColumnFamilyDescriptor>* column_families = nullptr);
 };
 
 } // namespace rocksdb

tools/ldb_cmd.cc

@@ -44,6 +44,7 @@ const string LDBCommand::ARG_PATH = "path";
 const string LDBCommand::ARG_HEX = "hex";
 const string LDBCommand::ARG_KEY_HEX = "key_hex";
 const string LDBCommand::ARG_VALUE_HEX = "value_hex";
+const string LDBCommand::ARG_CF_NAME = "column_family";
 const string LDBCommand::ARG_TTL = "ttl";
 const string LDBCommand::ARG_TTL_START = "start_time";
 const string LDBCommand::ARG_TTL_END = "end_time";
@@ -72,16 +73,14 @@ void DumpSstFile(std::string filename, bool output_hex, bool show_properties);
 };
 
 LDBCommand* LDBCommand::InitFromCmdLineArgs(
-  int argc,
-  char** argv,
-  const Options& options,
-  const LDBOptions& ldb_options
-) {
+    int argc, char** argv, const Options& options,
+    const LDBOptions& ldb_options,
+    const std::vector<ColumnFamilyDescriptor>* column_families) {
   vector<string> args;
   for (int i = 1; i < argc; i++) {
     args.push_back(argv[i]);
   }
-  return InitFromCmdLineArgs(args, options, ldb_options);
+  return InitFromCmdLineArgs(args, options, ldb_options, column_families);
 }
 
 /**
@@ -95,10 +94,9 @@ LDBCommand* LDBCommand::InitFromCmdLineArgs(
  * Returns nullptr if the command-line cannot be parsed.
  */
 LDBCommand* LDBCommand::InitFromCmdLineArgs(
-  const vector<string>& args,
-  const Options& options,
-  const LDBOptions& ldb_options
-) {
+    const vector<string>& args, const Options& options,
+    const LDBOptions& ldb_options,
+    const std::vector<ColumnFamilyDescriptor>* column_families) {
   // --x=y command line arguments are added as x->y map entries.
   map<string, string> option_map;
 
@@ -184,6 +182,8 @@ LDBCommand* LDBCommand::SelectCommand(
     return new ManifestDumpCommand(cmdParams, option_map, flags);
   } else if (cmd == ListColumnFamiliesCommand::Name()) {
     return new ListColumnFamiliesCommand(cmdParams, option_map, flags);
+  } else if (cmd == CreateColumnFamilyCommand::Name()) {
+    return new CreateColumnFamilyCommand(cmdParams, option_map, flags);
   } else if (cmd == DBFileDumperCommand::Name()) {
     return new DBFileDumperCommand(cmdParams, option_map, flags);
   } else if (cmd == InternalDumpCommand::Name()) {
@@ -450,6 +450,10 @@ void CompactorCommand::Help(string& ret) {
 }
 
 void CompactorCommand::DoCommand() {
+  if (!db_) {
+    assert(GetExecuteState().IsFailed());
+    return;
+  }
 
   Slice* begin = nullptr;
   Slice* end = nullptr;
@@ -513,6 +517,7 @@ Options DBLoaderCommand::PrepareOptionsForOpenDB() {
 
 void DBLoaderCommand::DoCommand() {
   if (!db_) {
+    assert(GetExecuteState().IsFailed());
     return;
   }
 
@@ -527,7 +532,7 @@ void DBLoaderCommand::DoCommand() {
     string key;
     string value;
     if (ParseKeyValue(line, &key, &value, is_key_hex_, is_value_hex_)) {
-      db_->Put(write_options, Slice(key), Slice(value));
+      db_->Put(write_options, GetCfHandle(), Slice(key), Slice(value));
     } else if (0 == line.find("Keys in range:")) {
       // ignore this line
     } else if (0 == line.find("Created bg thread 0x")) {
@@ -541,7 +546,7 @@ void DBLoaderCommand::DoCommand() {
     cout << "Warning: " << bad_lines << " bad lines ignored." << endl;
   }
   if (compact_) {
-    db_->CompactRange(CompactRangeOptions(), nullptr, nullptr);
+    db_->CompactRange(CompactRangeOptions(), GetCfHandle(), nullptr, nullptr);
   }
 }
 
@@ -696,6 +701,38 @@ void ListColumnFamiliesCommand::DoCommand() {
   }
 }
 
+void CreateColumnFamilyCommand::Help(string& ret) {
+  ret.append("  ");
+  ret.append(CreateColumnFamilyCommand::Name());
+  ret.append(" --db=<db_path> <new_column_family_name>");
+  ret.append("\n");
+}
+
+CreateColumnFamilyCommand::CreateColumnFamilyCommand(
+    const vector<string>& params, const map<string, string>& options,
+    const vector<string>& flags)
+    : LDBCommand(options, flags, true, {ARG_DB}) {
+  if (params.size() != 1) {
+    exec_state_ = LDBCommandExecuteResult::Failed(
+        "new column family name must be specified");
+  } else {
+    new_cf_name_ = params[0];
+  }
+}
+
+void CreateColumnFamilyCommand::DoCommand() {
+  ColumnFamilyHandle* new_cf_handle;
+  Status st = db_->CreateColumnFamily(options_, new_cf_name_, &new_cf_handle);
+  if (st.ok()) {
+    fprintf(stdout, "OK\n");
+  } else {
+    exec_state_ = LDBCommandExecuteResult::Failed(
+        "Fail to create new column family: " + st.ToString());
+  }
+  delete new_cf_handle;
+  CloseDB();
+}
+
 // ----------------------------------------------------------------------------
 
 namespace {
@@ -800,12 +837,13 @@ void InternalDumpCommand::Help(string& ret) {
 
 void InternalDumpCommand::DoCommand() {
   if (!db_) {
+    assert(GetExecuteState().IsFailed());
     return;
   }
 
   if (print_stats_) {
     string stats;
-    if (db_->GetProperty("rocksdb.stats", &stats)) {
+    if (db_->GetProperty(GetCfHandle(), "rocksdb.stats", &stats)) {
       fprintf(stdout, "%s\n", stats.c_str());
     }
   }
@@ -1050,7 +1088,7 @@ void DBDumperCommand::DoDumpCommand() {
   }
 
   // Setup key iterator
-  Iterator* iter = db_->NewIterator(ReadOptions());
+  Iterator* iter = db_->NewIterator(ReadOptions(), GetCfHandle());
   Status st = iter->status();
   if (!st.ok()) {
     exec_state_ =
@@ -1285,7 +1323,7 @@ void ReduceDBLevelsCommand::DoCommand() {
   }
   // Compact the whole DB to put all files to the highest level.
   fprintf(stdout, "Compacting the db...\n");
-  db_->CompactRange(CompactRangeOptions(), nullptr, nullptr);
+  db_->CompactRange(CompactRangeOptions(), GetCfHandle(), nullptr, nullptr);
   CloseDB();
 
   EnvOptions soptions;
@@ -1377,8 +1415,9 @@ void ChangeCompactionStyleCommand::DoCommand() {
   // print db stats before we have made any change
   std::string property;
   std::string files_per_level;
-  for (int i = 0; i < db_->NumberLevels(); i++) {
-    db_->GetProperty("rocksdb.num-files-at-level" + NumberToString(i),
+  for (int i = 0; i < db_->NumberLevels(GetCfHandle()); i++) {
+    db_->GetProperty(GetCfHandle(),
+                     "rocksdb.num-files-at-level" + NumberToString(i),
                      &property);
 
     // format print string
@@ -1393,13 +1432,14 @@ void ChangeCompactionStyleCommand::DoCommand() {
   CompactRangeOptions compact_options;
   compact_options.change_level = true;
   compact_options.target_level = 0;
-  db_->CompactRange(compact_options, nullptr, nullptr);
+  db_->CompactRange(compact_options, GetCfHandle(), nullptr, nullptr);
 
   // verify compaction result
   files_per_level = "";
   int num_files = 0;
   for (int i = 0; i < db_->NumberLevels(); i++) {
-    db_->GetProperty("rocksdb.num-files-at-level" + NumberToString(i),
+    db_->GetProperty(GetCfHandle(),
+                     "rocksdb.num-files-at-level" + NumberToString(i),
                      &property);
 
     // format print string
@@ -1622,8 +1662,12 @@ void GetCommand::Help(string& ret) {
 }
 
 void GetCommand::DoCommand() {
+  if (!db_) {
+    assert(GetExecuteState().IsFailed());
+    return;
+  }
   string value;
-  Status st = db_->Get(ReadOptions(), key_, &value);
+  Status st = db_->Get(ReadOptions(), GetCfHandle(), key_, &value);
   if (st.ok()) {
     fprintf(stdout, "%s\n",
               (is_value_hex_ ? StringToHex(value) : value).c_str());
@@ -1670,11 +1714,14 @@ void ApproxSizeCommand::Help(string& ret) {
 }
 
 void ApproxSizeCommand::DoCommand() {
-
+  if (!db_) {
+    assert(GetExecuteState().IsFailed());
+    return;
+  }
   Range ranges[1];
   ranges[0] = Range(start_key_, end_key_);
   uint64_t sizes[1];
-  db_->GetApproximateSizes(ranges, 1, sizes);
+  db_->GetApproximateSizes(GetCfHandle(), ranges, 1, sizes);
   fprintf(stdout, "%lu\n", (unsigned long)sizes[0]);
   /* Weird that GetApproximateSizes() returns void, although documentation
    * says that it returns a Status object.
@@ -1718,11 +1765,15 @@ void BatchPutCommand::Help(string& ret) {
 }
 
 void BatchPutCommand::DoCommand() {
+  if (!db_) {
+    assert(GetExecuteState().IsFailed());
+    return;
+  }
   WriteBatch batch;
 
   for (vector<pair<string, string>>::const_iterator itr
         = key_values_.begin(); itr != key_values_.end(); ++itr) {
-      batch.Put(itr->first, itr->second);
+    batch.Put(GetCfHandle(), itr->first, itr->second);
   }
   Status st = db_->Write(WriteOptions(), &batch);
   if (st.ok()) {
@@ -1798,9 +1849,13 @@ void ScanCommand::Help(string& ret) {
 }
 
 void ScanCommand::DoCommand() {
+  if (!db_) {
+    assert(GetExecuteState().IsFailed());
+    return;
+  }
 
   int num_keys_scanned = 0;
-  Iterator* it = db_->NewIterator(ReadOptions());
+  Iterator* it = db_->NewIterator(ReadOptions(), GetCfHandle());
   if (start_key_specified_) {
     it->Seek(start_key_);
   } else {
@@ -1896,7 +1951,11 @@ void DeleteCommand::Help(string& ret) {
 }
 
 void DeleteCommand::DoCommand() {
-  Status st = db_->Delete(WriteOptions(), key_);
+  if (!db_) {
+    assert(GetExecuteState().IsFailed());
+    return;
+  }
+  Status st = db_->Delete(WriteOptions(), GetCfHandle(), key_);
   if (st.ok()) {
     fprintf(stdout, "OK\n");
   } else {
@@ -1937,7 +1996,11 @@ void PutCommand::Help(string& ret) {
 }
 
 void PutCommand::DoCommand() {
-  Status st = db_->Put(WriteOptions(), key_, value_);
+  if (!db_) {
+    assert(GetExecuteState().IsFailed());
+    return;
+  }
+  Status st = db_->Put(WriteOptions(), GetCfHandle(), key_, value_);
   if (st.ok()) {
     fprintf(stdout, "OK\n");
   } else {
@@ -1978,6 +2041,7 @@ void DBQuerierCommand::Help(string& ret) {
 
 void DBQuerierCommand::DoCommand() {
   if (!db_) {
+    assert(GetExecuteState().IsFailed());
     return;
   }
 
@@ -2011,17 +2075,17 @@ void DBQuerierCommand::DoCommand() {
               "delete <key>\n");
     } else if (cmd == DELETE_CMD && tokens.size() == 2) {
       key = (is_key_hex_ ? HexToString(tokens[1]) : tokens[1]);
-      db_->Delete(write_options, Slice(key));
+      db_->Delete(write_options, GetCfHandle(), Slice(key));
       fprintf(stdout, "Successfully deleted %s\n", tokens[1].c_str());
     } else if (cmd == PUT_CMD && tokens.size() == 3) {
       key = (is_key_hex_ ? HexToString(tokens[1]) : tokens[1]);
       value = (is_value_hex_ ? HexToString(tokens[2]) : tokens[2]);
-      db_->Put(write_options, Slice(key), Slice(value));
+      db_->Put(write_options, GetCfHandle(), Slice(key), Slice(value));
       fprintf(stdout, "Successfully put %s %s\n",
               tokens[1].c_str(), tokens[2].c_str());
     } else if (cmd == GET_CMD && tokens.size() == 2) {
       key = (is_key_hex_ ? HexToString(tokens[1]) : tokens[1]);
-      if (db_->Get(read_options, Slice(key), &value).ok()) {
+      if (db_->Get(read_options, GetCfHandle(), Slice(key), &value).ok()) {
         fprintf(stdout, "%s\n", PrintKeyValue(key, value,
               is_key_hex_, is_value_hex_).c_str());
       } else {
@@ -2125,6 +2189,7 @@ void DBFileDumperCommand::Help(string& ret) {
 
 void DBFileDumperCommand::DoCommand() {
   if (!db_) {
+    assert(GetExecuteState().IsFailed());
     return;
   }
   Status s;

tools/ldb_cmd.h

@@ -44,6 +44,7 @@ public:
   static const string ARG_HEX;
   static const string ARG_KEY_HEX;
   static const string ARG_VALUE_HEX;
+  static const string ARG_CF_NAME;
   static const string ARG_TTL;
   static const string ARG_TTL_START;
   static const string ARG_TTL_END;
@@ -62,17 +63,14 @@ public:
   static const string ARG_CREATE_IF_MISSING;
 
   static LDBCommand* InitFromCmdLineArgs(
-    const vector<string>& args,
-    const Options& options,
-    const LDBOptions& ldb_options
-  );
+      const vector<string>& args, const Options& options,
+      const LDBOptions& ldb_options,
+      const std::vector<ColumnFamilyDescriptor>* column_families);
 
   static LDBCommand* InitFromCmdLineArgs(
-    int argc,
-    char** argv,
-    const Options& options,
-    const LDBOptions& ldb_options
-  );
+      int argc, char** argv, const Options& options,
+      const LDBOptions& ldb_options,
+      const std::vector<ColumnFamilyDescriptor>* column_families);
 
   bool ValidateCmdLineOptions();
 
@@ -82,6 +80,15 @@ public:
     options_ = options;
   }
 
+  virtual void SetColumnFamilies(
+      const std::vector<ColumnFamilyDescriptor>* column_families) {
+    if (column_families != nullptr) {
+      column_families_ = *column_families;
+    } else {
+      column_families_.clear();
+    }
+  }
+
   void SetLDBOptions(const LDBOptions& ldb_options) {
     ldb_options_ = ldb_options;
   }
@@ -90,10 +97,7 @@ public:
     return false;
   }
 
-  virtual ~LDBCommand() {
-    delete db_;
-    db_ = nullptr;
-  }
+  virtual ~LDBCommand() { CloseDB(); }
 
   /* Run the command, and return the execute result. */
   void Run() {
@@ -181,8 +185,10 @@ protected:
 
   LDBCommandExecuteResult exec_state_;
   string db_path_;
+  string column_family_name_;
   DB* db_;
   DBWithTTL* db_ttl_;
+  std::map<std::string, ColumnFamilyHandle*> cf_handles_;
 
   /**
    * true implies that this command can work if the db is opened in read-only
@@ -235,6 +241,13 @@ protected:
       db_path_ = itr->second;
     }
 
+    itr = options.find(ARG_CF_NAME);
+    if (itr != options.end()) {
+      column_family_name_ = itr->second;
+    } else {
+      column_family_name_ = kDefaultColumnFamilyName;
+    }
+
     is_key_hex_ = IsKeyHex(options, flags);
     is_value_hex_ = IsValueHex(options, flags);
     is_db_ttl_ = IsFlagPresent(flags, ARG_TTL);
@@ -248,21 +261,75 @@ protected:
     }
     // Open the DB.
     Status st;
+    std::vector<ColumnFamilyHandle*> handles_opened;
     if (is_db_ttl_) {
+      // ldb doesn't yet support TTL DB with multiple column families
+      if (!column_family_name_.empty() || !column_families_.empty()) {
+        exec_state_ = LDBCommandExecuteResult::Failed(
+            "ldb doesn't support TTL DB with multiple column families");
+      }
       if (is_read_only_) {
         st = DBWithTTL::Open(opt, db_path_, &db_ttl_, 0, true);
       } else {
         st = DBWithTTL::Open(opt, db_path_, &db_ttl_);
       }
       db_ = db_ttl_;
-    } else if (is_read_only_) {
-      st = DB::OpenForReadOnly(opt, db_path_, &db_);
     } else {
-      st = DB::Open(opt, db_path_, &db_);
+      if (column_families_.empty()) {
+        // Try to figure out column family lists
+        std::vector<std::string> cf_list;
+        st = DB::ListColumnFamilies(DBOptions(), db_path_, &cf_list);
+        // There is possible the DB doesn't exist yet, for "create if not
+        // "existing case". The failure is ignored here. We rely on DB::Open()
+        // to give us the correct error message for problem with opening
+        // existing DB.
+        if (st.ok() && cf_list.size() > 1) {
+          // Ignore single column family DB.
+          for (auto cf_name : cf_list) {
+            column_families_.emplace_back(cf_name, opt);
+          }
+        }
+      }
+      if (is_read_only_) {
+        if (column_families_.empty()) {
+          st = DB::OpenForReadOnly(opt, db_path_, &db_);
+        } else {
+          st = DB::OpenForReadOnly(opt, db_path_, column_families_,
+                                   &handles_opened, &db_);
+        }
+      } else {
+        if (column_families_.empty()) {
+          st = DB::Open(opt, db_path_, &db_);
+        } else {
+          st = DB::Open(opt, db_path_, column_families_, &handles_opened, &db_);
+        }
+      }
     }
     if (!st.ok()) {
       string msg = st.ToString();
       exec_state_ = LDBCommandExecuteResult::Failed(msg);
+    } else if (!handles_opened.empty()) {
+      assert(handles_opened.size() == column_families_.size());
+      bool found_cf_name = false;
+      for (size_t i = 0; i < handles_opened.size(); i++) {
+        cf_handles_[column_families_[i].name] = handles_opened[i];
+        if (column_family_name_ == column_families_[i].name) {
+          found_cf_name = true;
+        }
+      }
+      if (!found_cf_name) {
+        exec_state_ = LDBCommandExecuteResult::Failed(
+            "Non-existing column family " + column_family_name_);
+        CloseDB();
+      }
+    } else {
+      // We successfully opened DB in single column family mode.
+      assert(column_families_.empty());
+      if (column_family_name_ != kDefaultColumnFamilyName) {
+        exec_state_ = LDBCommandExecuteResult::Failed(
+            "Non-existing column family " + column_family_name_);
+        CloseDB();
+      }
     }
 
     options_ = opt;
@@ -270,11 +337,27 @@ protected:
 
   void CloseDB () {
     if (db_ != nullptr) {
+      for (auto& pair : cf_handles_) {
+        delete pair.second;
+      }
       delete db_;
       db_ = nullptr;
     }
   }
 
+  ColumnFamilyHandle* GetCfHandle() {
+    if (!cf_handles_.empty()) {
+      auto it = cf_handles_.find(column_family_name_);
+      if (it == cf_handles_.end()) {
+        exec_state_ = LDBCommandExecuteResult::Failed(
+            "Cannot find column family " + column_family_name_);
+      } else {
+        return it->second;
+      }
+    }
+    return db_->DefaultColumnFamily();
+  }
+
   static string PrintKeyValue(const string& key, const string& value,
         bool is_key_hex, bool is_value_hex) {
     string result;
@@ -310,10 +393,10 @@ protected:
    * passed in.
    */
   static vector<string> BuildCmdLineOptions(vector<string> options) {
-    vector<string> ret = {ARG_DB,               ARG_BLOOM_BITS,
-                          ARG_BLOCK_SIZE,       ARG_AUTO_COMPACTION,
-                          ARG_COMPRESSION_TYPE, ARG_WRITE_BUFFER_SIZE,
-                          ARG_FILE_SIZE,        ARG_FIX_PREFIX_LEN};
+    vector<string> ret = {ARG_DB, ARG_BLOOM_BITS, ARG_BLOCK_SIZE,
+                          ARG_AUTO_COMPACTION, ARG_COMPRESSION_TYPE,
+                          ARG_WRITE_BUFFER_SIZE, ARG_FILE_SIZE,
+                          ARG_FIX_PREFIX_LEN, ARG_CF_NAME};
     ret.insert(ret.end(), options.begin(), options.end());
     return ret;
   }
@@ -325,6 +408,7 @@ protected:
                          const string& option, string* value);
 
   Options options_;
+  std::vector<ColumnFamilyDescriptor> column_families_;
   LDBOptions ldb_options_;
 
 private:
@@ -568,6 +652,23 @@ class ListColumnFamiliesCommand : public LDBCommand {
   string dbname_;
 };
 
+class CreateColumnFamilyCommand : public LDBCommand {
+ public:
+  static string Name() { return "create_column_family"; }
+
+  CreateColumnFamilyCommand(const vector<string>& params,
+                            const map<string, string>& options,
+                            const vector<string>& flags);
+
+  static void Help(string& ret);
+  virtual void DoCommand() override;
+
+  virtual bool NoDBOpen() override { return false; }
+
+ private:
+  string new_cf_name_;
+};
+
 class ReduceDBLevelsCommand : public LDBCommand {
 public:
   static string Name() { return "reduce_levels"; }

tools/ldb_test.py

@@ -503,7 +503,36 @@ class LDBTestCase(unittest.TestCase):
         # Test on empty path.
         self.assertRunFAILFull(cmd % "")
 
-
+    def testColumnFamilies(self):
+        print "Running testColumnFamilies..."
+        dbPath = os.path.join(self.TMP_DIR, self.DB_NAME)
+        self.assertRunOK("put cf1_1 1 --create_if_missing", "OK")
+        self.assertRunOK("put cf1_2 2 --create_if_missing", "OK")
+        self.assertRunOK("put cf1_3 3", "OK")
+        # Given non-default column family to single CF DB.
+        self.assertRunFAIL("get cf1_1 --column_family=two")
+        self.assertRunOK("create_column_family two", "OK")
+        self.assertRunOK("put cf2_1 1 --create_if_missing --column_family=two",
+                         "OK")
+        self.assertRunOK("put cf2_2 2 --create_if_missing --column_family=two",
+                         "OK")
+        self.assertRunOK("delete cf1_2", "OK")
+        self.assertRunOK("create_column_family three", "OK")
+        self.assertRunOK("delete cf2_2 --column_family=two", "OK")
+        self.assertRunOK(
+            "put cf3_1 3 --create_if_missing --column_family=three",
+            "OK")
+        self.assertRunOK("get cf1_1 --column_family=default", "1")
+        self.assertRunOK("dump --column_family=two",
+                         "cf2_1 ==> 1\nKeys in range: 1")
+        self.assertRunOK("dump",
+                         "cf1_1 ==> 1\ncf1_3 ==> 3\nKeys in range: 2")
+        self.assertRunOK("get cf2_1 --column_family=two",
+                         "1")
+        self.assertRunOK("get cf3_1 --column_family=three",
+                         "3")
+        # non-existing column family.
+        self.assertRunFAIL("get cf3_1 --column_family=four")
 
 if __name__ == "__main__":
     unittest.main()

tools/ldb_tool.cc

@@ -30,6 +30,10 @@ public:
         " : Values are input/output as hex\n");
     ret.append("  --" + LDBCommand::ARG_HEX +
         " : Both keys and values are input/output as hex\n");
+    ret.append(
+        "  --" + LDBCommand::ARG_CF_NAME +
+        " : name of the column family to operate on. default: default column "
+        "family\n");
     ret.append("\n");
 
     ret.append("The following optional parameters control the database "
@@ -77,15 +81,16 @@ public:
     fprintf(stderr, "%s\n", ret.c_str());
   }
 
-  static void RunCommand(int argc, char** argv, Options options,
-                         const LDBOptions& ldb_options) {
+  static void RunCommand(
+      int argc, char** argv, Options options, const LDBOptions& ldb_options,
+      const std::vector<ColumnFamilyDescriptor>* column_families) {
     if (argc <= 2) {
       PrintHelp(argv[0]);
       exit(1);
     }
 
-    LDBCommand* cmdObj = LDBCommand::InitFromCmdLineArgs(argc, argv, options,
-                                                         ldb_options);
+    LDBCommand* cmdObj = LDBCommand::InitFromCmdLineArgs(
+        argc, argv, options, ldb_options, column_families);
     if (cmdObj == nullptr) {
       fprintf(stderr, "Unknown command\n");
       PrintHelp(argv[0]);
@@ -106,10 +111,11 @@ public:
 
 };
 
-
 void LDBTool::Run(int argc, char** argv, Options options,
-                  const LDBOptions& ldb_options) {
-  LDBCommandRunner::RunCommand(argc, argv, options, ldb_options);
+                  const LDBOptions& ldb_options,
+                  const std::vector<ColumnFamilyDescriptor>* column_families) {
+  LDBCommandRunner::RunCommand(argc, argv, options, ldb_options,
+                               column_families);
 }
 } // namespace rocksdb
 

tools/reduce_levels_test.cc

@@ -92,8 +92,8 @@ Status ReduceLevelTest::OpenDB(bool create_if_missing, int num_levels) {
 bool ReduceLevelTest::ReduceLevels(int target_level) {
   std::vector<std::string> args = rocksdb::ReduceDBLevelsCommand::PrepareArgs(
       dbname_, target_level, false);
-  LDBCommand* level_reducer = LDBCommand::InitFromCmdLineArgs(
-      args, Options(), LDBOptions());
+  LDBCommand* level_reducer =
+      LDBCommand::InitFromCmdLineArgs(args, Options(), LDBOptions(), nullptr);
   level_reducer->Run();
   bool is_succeed = level_reducer->GetExecuteState().IsSucceed();
   delete level_reducer;