feat: added namespace support

miftahDB · Sep 24, 2024 · aa41702 · aa41702
1 parent 1db814d
commit aa41702
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Showing 6 changed files with 359 additions and 42 deletions.
diff --git a/README.md b/README.md
@@ -34,6 +34,7 @@ Fast and lightweight key-value database library.
 ---
 
 ## 📖 Contents
+
 - [Features](#-features)
 - [Installation](#-installation)
 - [Usage](#usage)
@@ -401,6 +402,35 @@ Ensures all the changes are written to disk.
 db.flush();
 ```
 
+### `Namespace`
+
+Creates a namespaced database instance.
+
+- **Parameters**:
+  - `name`: The name of the namespace.
+- **Returns**:
+  - A new database instance with the namespace applied.
+
+```javascript
+// Create a new database instance with a namespace
+const db = new MiftahDB(":memory:");
+const users = db.namespace("users");
+
+// Set a value with a namespace
+users.set("852335", { name: "Ahmad" });
+console.log(users.get("852335"));
+
+// Other examples:
+// Will count the keys only on the "users" namespace
+users.count();
+
+// Will remove expired keys only on the "users" namespace
+users.cleanup();
+
+// Will remove all keys only on the "users" namespace
+users.flush();
+```
+
 ---
 
 ### `Execute`
@@ -486,17 +516,17 @@ try {
 
 **MiftahDB** supports various value types:
 
-|No | Type                      |
-| - | ----------                |
-| 1 | String                    |
-| 2 | Number                    |
-| 3 | Boolean                   |
-| 4 | Array                     |
-| 5 | Record (Object)           |
-| 6 | Date                      |
-| 7 | Buffer (Binary Data)      |
-| 8 | Uint8Array (Binary Data)  |
-| 9 | Null                      |
+| No  | Type                     |
+| --- | ------------------------ |
+| 1   | String                   |
+| 2   | Number                   |
+| 3   | Boolean                  |
+| 4   | Array                    |
+| 5   | Record (Object)          |
+| 6   | Date                     |
+| 7   | Buffer (Binary Data)     |
+| 8   | Uint8Array (Binary Data) |
+| 9   | Null                     |
 
 **Example for each type**:
 

diff --git a/src/base.ts b/src/base.ts
@@ -11,6 +11,7 @@ import { writeFileSync, readFileSync } from "node:fs";
 export abstract class BaseMiftahDB implements IMiftahDB {
   protected declare db: Database;
   protected statements: Record<string, Statement>;
+  private nameSpacePrefix: string | null = null;
 
   constructor(path = ":memory:") {
     this.initDatabase(path);
@@ -20,6 +21,16 @@ export abstract class BaseMiftahDB implements IMiftahDB {
     this.statements = this.prepareStatements();
   }
 
+  private addNamespacePrefix(k: string): string {
+    return this.nameSpacePrefix ? `${this.nameSpacePrefix}:${k}` : k;
+  }
+
+  private removeNamespacePrefix(key: string): string {
+    return this.nameSpacePrefix && key.startsWith(`${this.nameSpacePrefix}:`)
+      ? key.slice(this.nameSpacePrefix.length + 1)
+      : key;
+  }
+
   protected abstract initDatabase(path: string | ":memory:"): void;
 
   protected prepareStatements(): Record<string, Statement> {
@@ -42,10 +53,12 @@ export abstract class BaseMiftahDB implements IMiftahDB {
   }
 
   get<T>(key: string): T | null {
-    const result = this.statements.get.get(key) as MiftahDBItem | undefined;
+    const result = this.statements.get.get(this.addNamespacePrefix(key)) as
+      | MiftahDBItem
+      | undefined;
     if (!result) return null;
     if (result?.expires_at && result.expires_at <= Date.now()) {
-      this.delete(key);
+      this.delete(this.addNamespacePrefix(key));
       return null;
     }
     return decodeValue(result.value);
@@ -54,29 +67,40 @@ export abstract class BaseMiftahDB implements IMiftahDB {
   set<T extends MiftahValue>(key: string, value: T, expiresAt?: Date): void {
     const encodedValue = encodeValue(value);
     const expiresAtMs = expiresAt?.getTime() ?? null;
-    this.statements.set.run(key, encodedValue, expiresAtMs);
+    this.statements.set.run(
+      this.addNamespacePrefix(key),
+      encodedValue,
+      expiresAtMs
+    );
   }
 
   exists(key: string): boolean {
-    const result = this.statements.exists.get(key) as { [key: string]: number };
+    const result = this.statements.exists.get(this.addNamespacePrefix(key)) as {
+      [key: string]: number;
+    };
     return Boolean(Object.values(result)[0]);
   }
 
   delete(key: string): void {
-    this.statements.delete.run(key);
+    this.statements.delete.run(this.addNamespacePrefix(key));
   }
 
   rename(oldKey: string, newKey: string): void {
-    this.statements.rename.run(newKey, oldKey);
+    this.statements.rename.run(
+      this.addNamespacePrefix(newKey),
+      this.addNamespacePrefix(oldKey)
+    );
   }
 
   setExpire(key: string, expiresAt: Date): void {
     const expiresAtMs = expiresAt.getTime();
-    this.statements.setExpire.run(expiresAtMs, key);
+    this.statements.setExpire.run(expiresAtMs, this.addNamespacePrefix(key));
   }
 
   getExpire(key: string): Date | null {
-    const result = this.statements.getExpire.get(key) as
+    const result = this.statements.getExpire.get(
+      this.addNamespacePrefix(key)
+    ) as
       | {
           expires_at: number | null;
         }
@@ -85,27 +109,36 @@ export abstract class BaseMiftahDB implements IMiftahDB {
   }
 
   keys(pattern = "%"): string[] {
-    const result = this.statements.keys.all(pattern) as {
+    const result = this.statements.keys.all(
+      this.addNamespacePrefix(pattern)
+    ) as {
       key: string;
     }[];
-    return result.map((r) => r.key);
+    return result.map((r) => this.removeNamespacePrefix(r.key));
   }
 
   pagination(limit: number, page: number, pattern = "%"): string[] {
     const offset = (page - 1) * limit;
-    const result = this.statements.pagination.all(pattern, limit, offset) as {
-      key: string;
-    }[];
-    return result.map((r) => r.key);
+    const result = this.statements.pagination.all(
+      this.addNamespacePrefix(pattern),
+      limit,
+      offset
+    ) as { key: string }[];
+    return result.map((r) => this.removeNamespacePrefix(r.key));
   }
 
   count(pattern = "%"): number {
-    const result = this.statements.countKeys.get(pattern) as { count: number };
+    const result = this.statements.countKeys.get(
+      this.nameSpacePrefix ? `${this.nameSpacePrefix}:${pattern}` : pattern
+    ) as { count: number };
     return result.count;
   }
 
   countExpired(pattern = "%"): number {
-    const result = this.statements.countExpired.get(pattern) as {
+    const result = this.statements.countExpired.get(
+      Date.now(),
+      this.nameSpacePrefix ? `${this.nameSpacePrefix}:${pattern}` : pattern
+    ) as {
       count: number;
     };
     return result.count;
@@ -114,8 +147,9 @@ export abstract class BaseMiftahDB implements IMiftahDB {
   multiGet<T>(keys: string[]): Record<string, T | null> {
     const result: Record<string, T | null> = {};
     this.db.transaction(() => {
-      for (const key of keys) {
-        result[key] = this.get<T>(key);
+      for (const k of keys) {
+        const value = this.get<T>(this.addNamespacePrefix(k));
+        result[this.removeNamespacePrefix(k)] = value;
       }
     })();
     return result;
@@ -126,14 +160,16 @@ export abstract class BaseMiftahDB implements IMiftahDB {
   ): void {
     this.db.transaction(() => {
       for (const entry of entries) {
-        this.set(entry.key, entry.value, entry.expiresAt);
+        const key = this.addNamespacePrefix(entry.key);
+        this.set(key, entry.value, entry.expiresAt);
       }
     })();
   }
 
   multiDelete(keys: string[]): void {
     this.db.transaction(() => {
-      for (const key of keys) {
+      for (const k of keys) {
+        const key = this.addNamespacePrefix(k);
         this.delete(key);
       }
     })();
@@ -149,11 +185,11 @@ export abstract class BaseMiftahDB implements IMiftahDB {
   }
 
   cleanup(): void {
-    this.statements.cleanup.run(Date.now());
+    this.statements.cleanup.run(Date.now(), this.addNamespacePrefix("%"));
   }
 
   flush(): void {
-    this.statements.flush.run();
+    this.statements.flush.run(this.addNamespacePrefix("%"));
   }
 
   backup(path: string): void {
@@ -178,4 +214,12 @@ export abstract class BaseMiftahDB implements IMiftahDB {
     this.db = new DB(file);
     this.statements = this.prepareStatements();
   }
+
+  namespace(name: string): IMiftahDB {
+    const namespacedDB = Object.create(this);
+    namespacedDB.nameSpacePrefix = this.nameSpacePrefix
+      ? `${this.nameSpacePrefix}:${name}`
+      : name;
+    return namespacedDB;
+  }
 }
diff --git a/src/statements.ts b/src/statements.ts
@@ -10,7 +10,7 @@ export const SQL_STATEMENTS = {
 
   // Deletes rows that have expired
   CLEANUP:
-    "DELETE FROM miftahDB WHERE expires_at IS NOT NULL AND expires_at <= ?",
+    "DELETE FROM miftahDB WHERE expires_at IS NOT NULL AND expires_at <= ? AND key LIKE ?",
 
   // Renames a key
   RENAME: "UPDATE miftahDB SET key = ? WHERE key = ?",
@@ -32,7 +32,7 @@ export const SQL_STATEMENTS = {
   VACUUM: "VACUUM",
 
   // Deletes all rows from the table
-  FLUSH: "DELETE FROM miftahDB",
+  FLUSH: "DELETE FROM miftahDB WHERE key LIKE ?",
 
   // Returns true if the key exists, false otherwise
   EXISTS: "SELECT EXISTS (SELECT 1 FROM miftahDB WHERE key = ? LIMIT 1)",
@@ -54,7 +54,7 @@ export const SQL_STATEMENTS = {
 
   // Counts the number of expired rows in the table
   COUNT_EXPIRED:
-    "SELECT COUNT(*) as count FROM miftahDB WHERE (expires_at IS NOT NULL AND expires_at <= strftime('%s', 'now') * 1000) AND key LIKE ?",
+    "SELECT COUNT(*) as count FROM miftahDB WHERE (expires_at IS NOT NULL AND expires_at <= ?) AND key LIKE ?",
 
   // Creates the PRAGMA statements
   CREATE_PRAGMA: `

diff --git a/src/types.ts b/src/types.ts
@@ -24,7 +24,7 @@ export interface IMiftahDB<T extends MiftahValue = MiftahValue> {
    * @example
    * const value = db.get('user:1234');
    */
-  get(key: string): T | null;
+  get<K extends T>(key: string): K | null;
 
   /**
    * Sets a value in the database with an optional expiration.
@@ -35,7 +35,7 @@ export interface IMiftahDB<T extends MiftahValue = MiftahValue> {
    * @example
    * db.set('user:1234', { name: 'Ahmad' }, new Date('2023-12-31'));
    */
-  set(key: string, value: T, expiresAt?: Date): void;
+  set<K extends T>(key: string, value: K, expiresAt?: Date): void;
 
   /**
    * Gets the expiration date of a key.
@@ -107,7 +107,7 @@ export interface IMiftahDB<T extends MiftahValue = MiftahValue> {
    * // Get keys starting with "log", followed by exactly two characters, and ending with any number of characters
    * const logKeys = db.keys('log__:%');
    */
-  keys(pattern: string): string[];
+  keys(pattern?: string): string[];
 
   /**
    * Retrieves a paginated list of keys matching a pattern.
@@ -126,7 +126,7 @@ export interface IMiftahDB<T extends MiftahValue = MiftahValue> {
    * // Get the next 10 keys matching "user:%" (keys starting with "user:")
    * const secondUsersPage = db.pagination(10, 2, "user:%");
    */
-  pagination(limit: number, page: number, pattern: string): string[];
+  pagination(limit: number, page: number, pattern?: string): string[];
 
   /**
    * Counts the number of keys in the database.
@@ -164,7 +164,7 @@ export interface IMiftahDB<T extends MiftahValue = MiftahValue> {
    * @example
    * const values = db.multiGet(['user:1234', 'user:5678']);
    */
-  multiGet(keys: string[]): Record<string, T | null>;
+  multiGet<K extends T>(keys: string[]): Record<string, K | null>;
 
   /**
    * Sets multiple key-value pairs in the database with optional expirations.
@@ -176,7 +176,9 @@ export interface IMiftahDB<T extends MiftahValue = MiftahValue> {
    *   { key: 'user:5678', value: { name: 'Fatima' } }
    * ]);
    */
-  multiSet(entries: Array<{ key: string; value: T; expiresAt?: Date }>): void;
+  multiSet<K extends T>(
+    entries: Array<{ key: string; value: K; expiresAt?: Date }>
+  ): void;
 
   /**
    * Deletes multiple key-value pairs from the database.
@@ -255,6 +257,18 @@ export interface IMiftahDB<T extends MiftahValue = MiftahValue> {
    * console.log(db.get("key"));
    */
   restore(path: string): void;
+
+  /**
+   * Creates a namespaced database instance.
+   * - https://miftahdb.sqlite3.online/docs/api-reference/namespace
+   * @param name - The name of the namespace.
+   * @returns A new database instance with the namespace applied.
+   * @example
+   * const users = db.namespace("users");
+   * users.set("123", "value1");
+   * console.log(users.get("123"));
+   */
+  namespace(name: string): IMiftahDB<T>;
 }
 
 /**