@alcalzone/jsonl-db - npm Package Compare versions

Comparing version 0.5.1 to 1.0.0

build/lib/db.d.ts

@@ -9,9 +9,36 @@ import * as fs from "fs-extra";
     /**
-     * An optional reviver functionn (similar to JSON.parse) to transform parsed values before they are accessible in the database.
+     * An optional reviver function (similar to JSON.parse) to transform parsed values before they are accessible in the database.
      * If this function is defined, it must always return a value.
      */
-    reviver?: (key: string, value: any) => any;
+    reviver?: (key: string, value: any) => V;
+    /**
+     * Configure when the DB should be automatically compressed.
+     * If multiple conditions are configured, the DB is compressed when any of them are fulfilled
+     */
+    autoCompress?: Partial<{
+        /**
+         * Compress when uncompressedSize >= size * sizeFactor. Default: +Infinity
+         */
+        sizeFactor: number;
+        /**
+         * Configure the minimum size necessary for auto-compression based on size. Default: 0
+         */
+        sizeFactorMinimumSize: number;
+        /**
+         * Compress after a certain time has passed. Default: never
+         */
+        intervalMs: number;
+        /**
+         * Configure the minimum count of changes for auto-compression based on time. Default: 1
+         */
+        intervalMinChanges: number;
+        /** Compress when closing the DB. Default: false */
+        onClose: boolean;
+        /** Compress after opening the DB. Default: false */
+        onOpen: boolean;
+    }>;
 }
 export declare class JsonlDB<V extends unknown = unknown> {
     constructor(filename: string, options?: JsonlDBOptions<V>);
+    private validateOptions;
     readonly filename: string;
@@ -29,2 +56,6 @@ readonly dumpFilename: string;
     get size(): number;
+    private _uncompressedSize;
+    /** Returns the line count of the appendonly file, excluding empty lines */
+    get uncompressedSize(): number;
+    private _changesSinceLastCompress;
     private _isOpen;
@@ -37,2 +68,3 @@ get isOpen(): boolean;
     private _dumpBacklog;
+    private compressInterval;
     private _openPromise;
@@ -49,2 +81,8 @@ open(): Promise<void>;
     exportJson(filename: string, options?: fs.WriteOptions): Promise<void>;
+    private updateStatistics;
+    private needToCompress;
+    /**
+     * Writes a line into the correct backlog
+     * @param noAutoCompress Whether auto-compression should be disabled
+     */
     private write;
@@ -56,2 +94,3 @@ private entryToLine;
     private writeThread;
+    private compressPromise;
     /** Compresses the db by dumping it and overwriting the aof file. */
@@ -58,0 +97,0 @@ compress(): Promise<void>;

build/lib/db.js

@@ -17,4 +17,8 @@ "use strict";
     constructor(filename, options = {}) {
+        var _a;
         this._db = new Map();
+        this._uncompressedSize = Number.NaN;
+        this._changesSinceLastCompress = 0;
         this._isOpen = false;
+        this.validateOptions(options);
         this.filename = filename;
@@ -31,6 +35,40 @@ this.dumpFilename = this.filename + ".dump";
         this[Symbol.iterator] = this._db[Symbol.iterator].bind(this._db);
+        // Start regular auto-compression
+        const { intervalMs, intervalMinChanges = 1 } = (_a = options.autoCompress) !== null && _a !== void 0 ? _a : {};
+        if (intervalMs) {
+            this.compressInterval = setInterval(() => {
+                if (this._changesSinceLastCompress >= intervalMinChanges) {
+                    void this.compress();
+                }
+            }, intervalMs);
+        }
     }
+    validateOptions(options) {
+        if (options.autoCompress) {
+            const { sizeFactor, sizeFactorMinimumSize, intervalMs, intervalMinChanges, } = options.autoCompress;
+            if (sizeFactor != undefined && sizeFactor <= 1) {
+                throw new Error("sizeFactor must be > 1");
+            }
+            if (sizeFactorMinimumSize != undefined &&
+                sizeFactorMinimumSize < 0) {
+                throw new Error("sizeFactorMinimumSize must be >= 0");
+            }
+            if (intervalMs != undefined && intervalMs < 10) {
+                throw new Error("intervalMs must be >= 10");
+            }
+            if (intervalMinChanges != undefined && intervalMinChanges < 1) {
+                throw new Error("intervalMinChanges must be >= 1");
+            }
+        }
+    }
     get size() {
         return this._db.size;
     }
+    /** Returns the line count of the appendonly file, excluding empty lines */
+    get uncompressedSize() {
+        if (!this._isOpen) {
+            throw new Error("The database is not open!");
+        }
+        return this._uncompressedSize;
+    }
     get isOpen() {
@@ -41,2 +79,3 @@ return this._isOpen;
     async open() {
+        var _a;
         // Open the file for appending and reading
@@ -51,2 +90,3 @@ this._fd = await fs.open(this.filename, "a+");
         let lineNo = 0;
+        this._uncompressedSize = 0;
         try {
@@ -61,2 +101,3 @@ await new Promise((resolve, reject) => {
                     try {
+                        this._uncompressedSize++;
                         this.parseLine(line);
@@ -87,2 +128,5 @@ }
         this._isOpen = true;
+        if ((_a = this.options.autoCompress) === null || _a === void 0 ? void 0 : _a.onOpen) {
+            await this.compress();
+        }
     }
@@ -146,3 +190,3 @@ /** Parses a line and updates the internal DB correspondingly */
             this._db.set(key, value);
-            this.write(this.entryToLine(key, value));
+            this.write(this.entryToLine(key, value), true);
         }
@@ -157,9 +201,43 @@ }
     // TODO: use cork() and uncork() to throttle filesystem accesses
-    write(line) {
+    updateStatistics(command) {
+        if (command === "") {
+            this._uncompressedSize = 0;
+        }
+        else {
+            this._uncompressedSize++;
+        }
+        this._changesSinceLastCompress++;
+    }
+    needToCompress() {
+        var _a;
+        // compression is busy?
+        if (this.compressPromise)
+            return false;
+        const { sizeFactor = Number.POSITIVE_INFINITY, sizeFactorMinimumSize = 0, } = (_a = this.options.autoCompress) !== null && _a !== void 0 ? _a : {};
+        if (this.uncompressedSize >= sizeFactorMinimumSize &&
+            this.uncompressedSize >= sizeFactor * this.size) {
+            return true;
+        }
+        return false;
+    }
+    /**
+     * Writes a line into the correct backlog
+     * @param noAutoCompress Whether auto-compression should be disabled
+     */
+    write(line, noAutoCompress = false) {
         /* istanbul ignore else */
         if (this._compressBacklog && !this._compressBacklog.destroyed) {
+            // The compress backlog handling also handles the file statistics
             this._compressBacklog.write(line);
         }
         else if (this._writeBacklog && !this._writeBacklog.destroyed) {
-            this._writeBacklog.write(line);
+            // Update line statistics
+            this.updateStatistics(line);
+            // Either compress or write to the main file, never both
+            if (!noAutoCompress && this.needToCompress()) {
+                this.compress();
+            }
+            else {
+                this._writeBacklog.write(line);
+            }
         }
@@ -246,4 +324,9 @@ else {
     async compress() {
-        if (!this._writeBacklog)
+        if (!this._writeBacklog || this.compressPromise)
             return;
+        this.compressPromise = deferred_promise_1.createDeferredPromise();
+        // Immediately remember the database size or writes while compressing
+        // will be incorrectly reflected
+        this._uncompressedSize = this.size;
+        this._changesSinceLastCompress = 0;
         await this.dump();
@@ -269,2 +352,3 @@ // After dumping, restart the write thread so no duplicate entries get written
         while (null !== (line = this._compressBacklog.read())) {
+            this.updateStatistics(line);
             this._writeBacklog.write(line);
@@ -274,7 +358,20 @@ }
         this._compressBacklog = undefined;
+        // If any method is waiting for the compress process, signal it that we're done
+        this.compressPromise.resolve();
+        this.compressPromise = undefined;
     }
     /** Closes the DB and waits for all data to be written */
     async close() {
-        var _a;
+        var _a, _b;
         this._isOpen = false;
+        if (this.compressInterval)
+            clearInterval(this.compressInterval);
+        if (this.compressPromise) {
+            // Wait until any pending compress processes are complete
+            await this.compressPromise;
+        }
+        else if ((_a = this.options.autoCompress) === null || _a === void 0 ? void 0 : _a.onClose) {
+            // Compress if required
+            await this.compress();
+        }
         if (this._writeBacklog) {
@@ -286,3 +383,3 @@ this._closeDBPromise = deferred_promise_1.createDeferredPromise();
             // Disable writing into the dump backlog stream
-            (_a = this._dumpBacklog) === null || _a === void 0 ? void 0 : _a.end();
+            (_b = this._dumpBacklog) === null || _b === void 0 ? void 0 : _b.end();
             this._dumpBacklog = undefined;
@@ -289,0 +386,0 @@ await this._closeDBPromise;

package.json

 {
   "name": "@alcalzone/jsonl-db",
-  "version": "0.5.1",
+  "version": "1.0.0",
   "description": "Simple JSONL-based key-value store",
@@ -5,0 +5,0 @@ "main": "./build/index.js",

README.md

@@ -32,3 +32,3 @@ # jsonl-db
 if (db.has("key")) {
-  result = db.get("key");
+	result = db.get("key");
 }
@@ -47,3 +47,3 @@ // ...forEach, keys(), entries(), values(), ...
 function reviver(key: string, value: any) {
-  // MUST return a value. If you don't want to transform `value`, return it.
+	// MUST return a value. If you don't want to transform `value`, return it.
 }
@@ -68,3 +68,3 @@
 
-After a while, the main db file may contain unnecessary entries. To remove them, use the `compress()` method.
+After a while, the main db file may contain unnecessary entries. The raw number of entries can be read using the `uncompressedSize` property. To remove unnecessary entries, use the `compress()` method.
 
@@ -77,2 +77,16 @@ ```ts
 
+The database can automatically compress the database file under some conditions. To do so, use the `autoCompress` parameter of the constructor options:
+```ts
+const db = new DB("/path/to/file", { autoCompress: { /* auto compress options */ }});
+```
+The following options exist (all optional) and can be combined:
+| Option | Default | Description |
+|-----------------|---------|-------------|
+| sizeFactor | +Infinity | Compress when `uncompressedSize >= size * sizeFactor` |
+| sizeFactorMinimumSize | 0 | Configure the minimum size necessary for auto-compression based on size |
+| intervalMs | +Infinity | Compress after a certain time has passed |
+| intervalMinChanges | 1 | Configure the minimum count of changes for auto-compression based on time |
+| onClose | false | Compress when closing the DB |
+| onOpen | false | Compress after opening the DB |
+
 Importing JSON files can be done this way:
@@ -100,2 +114,5 @@ ```ts
 
+### 1.0.0 (2020-04-29)
+Added auto-compress functionality
+
 ### 0.5.1 (2020-04-28)
@@ -102,0 +119,0 @@ Fix: The main export no longer exports `JsonlDB` as `DB`.

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Improved metrics

Total package byte prevSize

43328

increased by28.43%

Lines of code

490

increased by38.42%

Number of low quality alerts

0

decreased by-100%

Number of lines in readme file

141

increased by13.71%

No dependency changes