From 20dff26b3f729b28b8af48e2791f90823f8c5458 Mon Sep 17 00:00:00 2001
From: Steven Hartland <stevenmhartland@gmail.com>
Date: Wed, 17 May 2023 12:17:30 +0100
Subject: [PATCH] chore: use 8 character hash components

Use 8 character hash components to reduce the key length, making it
more readable.

Fixes #97
---
 CHANGELOG.md          |  1 +
 dist/restore/index.js | 14 ++++++++++++--
 dist/save/index.js    | 14 ++++++++++++--
 src/config.ts         | 15 +++++++++++++--
 4 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d0968ff..ba91b96 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## 2.3.1
 
 - Fix cache key stability.
+- Use 8 character hash components to reduce the key length, making it more readable.
 
 ## 2.3.0
 
diff --git a/dist/restore/index.js b/dist/restore/index.js
index 39525a6..70116b5 100644
--- a/dist/restore/index.js
+++ b/dist/restore/index.js
@@ -60028,6 +60028,7 @@ class Workspace {
 const HOME = external_os_default().homedir();
 const config_CARGO_HOME = process.env.CARGO_HOME || external_path_default().join(HOME, ".cargo");
 const STATE_CONFIG = "RUST_CACHE_CONFIG";
+const HASH_LENGTH = 8;
 class CacheConfig {
     constructor() {
         /** All the paths we want to cache */
@@ -60103,7 +60104,7 @@ class CacheConfig {
             }
         }
         self.keyEnvs = keyEnvs;
-        key += `-${hasher.digest("hex")}`;
+        key += `-${digest(hasher)}`;
         self.restoreKey = key;
         // Construct the lockfiles portion of the key:
         // This considers all the files found via globbing for various manifests
@@ -60132,7 +60133,7 @@ class CacheConfig {
                 hasher.update(chunk);
             }
         }
-        let lockHash = hasher.digest("hex");
+        let lockHash = digest(hasher);
         self.keyFiles = keyFiles;
         key += `-${lockHash}`;
         self.cacheKey = key;
@@ -60214,6 +60215,15 @@ class CacheConfig {
 function isCacheUpToDate() {
     return core.getState(STATE_CONFIG) === "";
 }
+/**
+ * Returns a hex digest of the given hasher truncated to `HASH_LENGTH`.
+ *
+ * @param hasher The hasher to digest.
+ * @returns The hex digest.
+ */
+function digest(hasher) {
+    return hasher.digest("hex").substring(0, HASH_LENGTH);
+}
 async function getRustVersion() {
     const stdout = await getCmdOutput("rustc", ["-vV"]);
     let splits = stdout
diff --git a/dist/save/index.js b/dist/save/index.js
index c0bd395..6cbb891 100644
--- a/dist/save/index.js
+++ b/dist/save/index.js
@@ -60028,6 +60028,7 @@ class Workspace {
 const HOME = external_os_default().homedir();
 const CARGO_HOME = process.env.CARGO_HOME || external_path_default().join(HOME, ".cargo");
 const STATE_CONFIG = "RUST_CACHE_CONFIG";
+const HASH_LENGTH = 8;
 class CacheConfig {
     constructor() {
         /** All the paths we want to cache */
@@ -60103,7 +60104,7 @@ class CacheConfig {
             }
         }
         self.keyEnvs = keyEnvs;
-        key += `-${hasher.digest("hex")}`;
+        key += `-${digest(hasher)}`;
         self.restoreKey = key;
         // Construct the lockfiles portion of the key:
         // This considers all the files found via globbing for various manifests
@@ -60132,7 +60133,7 @@ class CacheConfig {
                 hasher.update(chunk);
             }
         }
-        let lockHash = hasher.digest("hex");
+        let lockHash = digest(hasher);
         self.keyFiles = keyFiles;
         key += `-${lockHash}`;
         self.cacheKey = key;
@@ -60214,6 +60215,15 @@ class CacheConfig {
 function isCacheUpToDate() {
     return core.getState(STATE_CONFIG) === "";
 }
+/**
+ * Returns a hex digest of the given hasher truncated to `HASH_LENGTH`.
+ *
+ * @param hasher The hasher to digest.
+ * @returns The hex digest.
+ */
+function digest(hasher) {
+    return hasher.digest("hex").substring(0, HASH_LENGTH);
+}
 async function getRustVersion() {
     const stdout = await getCmdOutput("rustc", ["-vV"]);
     let splits = stdout
diff --git a/src/config.ts b/src/config.ts
index 64e161c..a612940 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -13,6 +13,7 @@ const HOME = os.homedir();
 export const CARGO_HOME = process.env.CARGO_HOME || path.join(HOME, ".cargo");
 
 const STATE_CONFIG = "RUST_CACHE_CONFIG";
+const HASH_LENGTH = 8;
 
 export class CacheConfig {
   /** All the paths we want to cache */
@@ -105,7 +106,7 @@ export class CacheConfig {
 
     self.keyEnvs = keyEnvs;
 
-    key += `-${hasher.digest("hex")}`;
+    key += `-${digest(hasher)}`;
 
     self.restoreKey = key;
 
@@ -144,7 +145,7 @@ export class CacheConfig {
         hasher.update(chunk);
       }
     }
-    let lockHash = hasher.digest("hex");
+    let lockHash = digest(hasher);
 
     self.keyFiles = keyFiles;
 
@@ -239,6 +240,16 @@ export function isCacheUpToDate(): boolean {
   return core.getState(STATE_CONFIG) === "";
 }
 
+/**
+ * Returns a hex digest of the given hasher truncated to `HASH_LENGTH`.
+ *
+ * @param hasher The hasher to digest.
+ * @returns The hex digest.
+ */
+function digest(hasher: crypto.Hash): string {
+  return hasher.digest("hex").substring(0, HASH_LENGTH);
+}
+
 interface RustVersion {
   host: string;
   release: string;