From 48b6393f9ac84cbc49239b3ee5bf7a9865a6dc78 Mon Sep 17 00:00:00 2001
From: lifegpc <g1710431395@gmail.com>
Date: Sun, 21 May 2023 09:23:46 +0800
Subject: [PATCH] Update db lock cross 2 process

---
 db.ts    | 21 ++++++++++++++++++++-
 utils.ts | 11 +++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/db.ts b/db.ts
index 54789d0..d44c583 100644
--- a/db.ts
+++ b/db.ts
@@ -106,8 +106,10 @@ export class EhDb {
     db;
     flock_enabled: boolean = eval('typeof Deno.flock !== "undefined"');
     #file: Deno.FsFile | undefined;
+    #dblock: Deno.FsFile | undefined;
     _exist_table: Set<string> = new Set();
     #lock_file: string | undefined;
+    #dblock_file: string | undefined;
     readonly version = new SemVer("1.0.0-0");
     constructor(base_path: string) {
         this.db = new DB(join(base_path, "data.db"));
@@ -115,10 +117,16 @@ export class EhDb {
         if (!this._check_database()) this._create_table();
         if (this.flock_enabled) {
             this.#lock_file = join(base_path, "db.lock");
+            this.#dblock_file = join(base_path, "eh.locked");
             this.#file = Deno.openSync(this.#lock_file, {
                 create: true,
                 write: true,
             });
+            this.#dblock = Deno.openSync(this.#dblock_file, {
+                create: true,
+                write: true,
+            });
+            this.dblock();
         } else {
             console.log(
                 "%cFile locking is disabled. Use --unstable to enable file locking.",
@@ -230,7 +238,10 @@ export class EhDb {
         this.db.close();
         if (this.#file) {
             this.#file.close();
-            if (this.#lock_file) Deno.removeSync(this.#lock_file);
+        }
+        if (this.#dblock) {
+            this.dbunlock();
+            this.#dblock.close();
         }
     }
     async commit() {
@@ -266,10 +277,18 @@ export class EhDb {
         if (!this.#file) return;
         await eval(`Deno.flock(${this.#file.rid}, true);`);
     }
+    dblock() {
+        if (!this.#dblock) return;
+        eval(`Deno.flockSync(${this.#dblock.rid}, true);`);
+    }
     async funlock() {
         if (!this.#file) return;
         await eval(`Deno.funlock(${this.#file.rid});`);
     }
+    dbunlock() {
+        if (!this.#dblock) return;
+        eval(`Deno.funlockSync(${this.#dblock.rid});`);
+    }
     get_gmeta_by_gid(gid: number) {
         const s = this.convert_gmeta(
             this.db.queryEntries<GMetaRaw>(
diff --git a/utils.ts b/utils.ts
index 5dd2b92..334650e 100644
--- a/utils.ts
+++ b/utils.ts
@@ -60,3 +60,14 @@ export function parse_bool(s: string) {
     const l = s.toLowerCase();
     return l === "true" || l === "yes";
 }
+
+export function try_remove_sync(
+    s: string,
+    o: Deno.RemoveOptions | undefined = undefined,
+) {
+    try {
+        Deno.removeSync(s, o);
+    } catch (_) {
+        return;
+    }
+}