Export rename(base, file) on BaseDb

packages/db/src/FileFlatDb/index.ts

@@ -29,6 +29,8 @@ const l = logger('db/flat');
 export default class FileFlatDb implements BaseDb {
   private _fd: number;
   private _fileSize: number = 0;
+  private _base: string;
+  private _path: string;
   private _file: string;
   private _isCompressed: boolean;
   private _lruBranch: LRUMap<number, Buffer>;
@@ -36,7 +38,9 @@ export default class FileFlatDb implements BaseDb {
 
   constructor (base: string, file: string = defaults.DEFAULT_FILE, options: BaseDbOptions = {}) {
     this._fd = -1;
-    this._file = path.join(base, file);
+    this._base = base;
+    this._file = file;
+    this._path = path.join(base, file);
     this._lruBranch = new LRUMap(LRU_BRANCH_COUNT);
     this._lruData = new LRUMap(LRU_DATA_COUNT);
     this._isCompressed = options && !isUndefined(options.isCompressed)
@@ -47,7 +51,7 @@ export default class FileFlatDb implements BaseDb {
   }
 
   open (): void {
-    this._fd = this._open(this._file);
+    this._fd = this._open(this._path);
     this._fileSize = fs.fstatSync(this._fd).size;
 
     this._lruBranch.clear();
@@ -66,10 +70,22 @@ export default class FileFlatDb implements BaseDb {
   empty (): void {
     this.close();
 
-    this._fd = this._open(this._file, true);
+    this._fd = this._open(this._path, true);
     this._fileSize = fs.fstatSync(this._fd).size;
   }
 
+  rename (base: string, file: string): void {
+    assert(this._fd === -1, 'Database cannot be open for renaming');
+
+    const oldPath = this._path;
+
+    this._base = base;
+    this._file = file;
+    this._path = path.join(base, file);
+
+    fs.renameSync(oldPath, this._path);
+  }
+
   maintain (fn: ProgressCb): void {
     assert(this._fd === -1, 'Database cannot be open for compacting');
 

packages/db/src/engines/FileTreeDb.ts

@@ -51,7 +51,11 @@ export default class FileTreeDb implements BaseDb {
   }
 
   empty (): void {
-    throw new Error('error is not implemented');
+    l.error('empty() is not implemented');
+  }
+
+  rename (base: string, file: string): void {
+    l.error('rename() is not implemented');
   }
 
   maintain (fn: ProgressCb): void {

packages/db/src/engines/LruDb.ts

@@ -45,6 +45,10 @@ export default class LruDb implements BaseDb {
     this.backing.empty();
   }
 
+  rename (base: string, file: string): void {
+    this.backing.rename(base, file);
+  }
+
   maintain (fn: ProgressCb): void {
     this.backing.maintain(fn);
   }

packages/db/src/engines/MemoryDb.ts

@@ -31,6 +31,10 @@ export default class MemoryDb implements BaseDb {
     this.storage = {};
   }
 
+  rename (base: string, file: string): void {
+    l.error('rename() is not implemented');
+  }
+
   maintain (fn: ProgressCb): void {
     fn({
       isCompleted: true,

packages/db/src/engines/TransactionDb.ts

@@ -62,6 +62,10 @@ export default class TransactionDb implements TxDb {
     this.backing.empty();
   }
 
+  rename (base: string, file: string): void {
+    this.backing.rename(base, file);
+  }
+
   maintain (fn: ProgressCb): void {
     assert(this.txStarted === false, 'Cannot maintain inside an open transaction');
 

packages/db/src/types.d.ts

@@ -18,6 +18,7 @@ export interface BaseDb {
   close (): void;
   open (): void;
   empty (): void;
+  rename (base: string, file: string): void;
 
   maintain (fn: ProgressCb): void;