From 2df6db36c85c27d424d54e9c168ef4ea09c5c08c Mon Sep 17 00:00:00 2001
From: Ryan Dahl <ry@tinyclouds.org>
Date: Wed, 26 Apr 2023 13:14:01 -0400
Subject: [PATCH] feat(ext/kv): add more atomic operation helpers (#18854)

Co-authored-by: losfair <zhy20000919@hotmail.com>
Co-authored-by: Luca Casonato <hello@lcas.dev>
---
 cli/tests/unit/kv_test.ts          | 30 ++++++++++++++++++++++++++++++
 cli/tsc/dts/lib.deno.unstable.d.ts | 19 +++++++++++++++++--
 ext/kv/01_db.ts                    | 23 +++++++++++++++--------
 3 files changed, 62 insertions(+), 10 deletions(-)

diff --git a/cli/tests/unit/kv_test.ts b/cli/tests/unit/kv_test.ts
index 60cf11b8ef..0af8f338d2 100644
--- a/cli/tests/unit/kv_test.ts
+++ b/cli/tests/unit/kv_test.ts
@@ -219,6 +219,36 @@ dbTest("compare and mutate not exists", async (db) => {
   assertEquals(res, null);
 });
 
+dbTest("atomic mutation helper (sum)", async (db) => {
+  await db.set(["t"], new Deno.KvU64(42n));
+  assertEquals((await db.get(["t"])).value, new Deno.KvU64(42n));
+
+  await db.atomic().sum(["t"], 1n).commit();
+  assertEquals((await db.get(["t"])).value, new Deno.KvU64(43n));
+});
+
+dbTest("atomic mutation helper (min)", async (db) => {
+  await db.set(["t"], new Deno.KvU64(42n));
+  assertEquals((await db.get(["t"])).value, new Deno.KvU64(42n));
+
+  await db.atomic().min(["t"], 1n).commit();
+  assertEquals((await db.get(["t"])).value, new Deno.KvU64(1n));
+
+  await db.atomic().min(["t"], 2n).commit();
+  assertEquals((await db.get(["t"])).value, new Deno.KvU64(1n));
+});
+
+dbTest("atomic mutation helper (max)", async (db) => {
+  await db.set(["t"], new Deno.KvU64(42n));
+  assertEquals((await db.get(["t"])).value, new Deno.KvU64(42n));
+
+  await db.atomic().max(["t"], 41n).commit();
+  assertEquals((await db.get(["t"])).value, new Deno.KvU64(42n));
+
+  await db.atomic().max(["t"], 43n).commit();
+  assertEquals((await db.get(["t"])).value, new Deno.KvU64(43n));
+});
+
 dbTest("compare multiple and mutate", async (db) => {
   await db.set(["t1"], "1");
   await db.set(["t2"], "2");
diff --git a/cli/tsc/dts/lib.deno.unstable.d.ts b/cli/tsc/dts/lib.deno.unstable.d.ts
index cf6cedf414..dc3bfcfc01 100644
--- a/cli/tsc/dts/lib.deno.unstable.d.ts
+++ b/cli/tsc/dts/lib.deno.unstable.d.ts
@@ -1646,7 +1646,8 @@ declare namespace Deno {
    * - `sum` - Adds the given value to the existing value of the key. Both the
    *   value specified in the mutation, and any existing value must be of type
    *   `Deno.KvU64`. If the key does not exist, the value is set to the given
-   *   value (summed with 0).
+   *   value (summed with 0). If the result of the sum overflows an unsigned
+   *   64-bit integer, the result is wrapped around.
    * - `max` - Sets the value of the key to the maximum of the existing value
    *   and the given value. Both the value specified in the mutation, and any
    *   existing value must be of type `Deno.KvU64`. If the key does not exist,
@@ -1845,9 +1846,23 @@ declare namespace Deno {
      */
     mutate(...mutations: KvMutation[]): this;
     /**
-     * Shortcut for creating a sum mutation.
+     * Shortcut for creating a `sum` mutation. This method wraps `n` in a
+     * {@linkcode Deno.KvU64}, so the value of `n` must be in the range
+     * `[0, 2^64-1]`.
      */
     sum(key: KvKey, n: bigint): this;
+    /**
+     * Shortcut for creating a `min` mutation. This method wraps `n` in a
+     * {@linkcode Deno.KvU64}, so the value of `n` must be in the range
+     * `[0, 2^64-1]`.
+     */
+    min(key: KvKey, n: bigint): this;
+    /**
+     * Shortcut for creating a `max` mutation. This method wraps `n` in a
+     * {@linkcode Deno.KvU64}, so the value of `n` must be in the range
+     * `[0, 2^64-1]`.
+     */
+    max(key: KvKey, n: bigint): this;
     /**
      * Add to the operation a mutation that sets the value of the specified key
      * to the specified value if all checks pass during the commit.
diff --git a/ext/kv/01_db.ts b/ext/kv/01_db.ts
index 1a7b27dac7..da29a09521 100644
--- a/ext/kv/01_db.ts
+++ b/ext/kv/01_db.ts
@@ -211,14 +211,6 @@ class AtomicOperation {
     return this;
   }
 
-  sum(key: Deno.KvKey, n: bigint): this {
-    return this.mutate({
-      type: "sum",
-      key,
-      value: new KvU64(n),
-    });
-  }
-
   mutate(...mutations: Deno.KvMutation[]): this {
     for (const mutation of mutations) {
       const key = mutation.key;
@@ -249,6 +241,21 @@ class AtomicOperation {
     return this;
   }
 
+  sum(key: Deno.KvKey, n: bigint): this {
+    this.#mutations.push([key, "sum", serializeValue(new KvU64(n))]);
+    return this;
+  }
+
+  min(key: Deno.KvKey, n: bigint): this {
+    this.#mutations.push([key, "min", serializeValue(new KvU64(n))]);
+    return this;
+  }
+
+  max(key: Deno.KvKey, n: bigint): this {
+    this.#mutations.push([key, "max", serializeValue(new KvU64(n))]);
+    return this;
+  }
+
   set(key: Deno.KvKey, value: unknown): this {
     this.#mutations.push([key, "set", serializeValue(value)]);
     return this;