Implementation of python's caching (#266)

src/cache-distributions/pipenv-cache.ts

@@ -0,0 +1,44 @@
+import * as glob from '@actions/glob';
+import * as os from 'os';
+import * as path from 'path';
+import * as core from '@actions/core';
+
+import CacheDistributor from './cache-distributor';
+
+class PipenvCache extends CacheDistributor {
+  constructor(
+    private pythonVersion: string,
+    protected patterns: string = '**/Pipfile.lock'
+  ) {
+    super('pipenv', patterns);
+  }
+
+  protected async getCacheGlobalDirectories() {
+    let virtualEnvRelativePath;
+
+    // Default virtualenv directories are hardcoded,
+    // because pipenv is not preinstalled on hosted images and virtualenv is not created:
+    // https://github.com/pypa/pipenv/blob/1daaa0de9a0b00d386c6baeb809d8d4ee6795cfd/pipenv/utils.py#L1990-L2002
+    if (process.platform === 'win32') {
+      virtualEnvRelativePath = '.virtualenvs';
+    } else {
+      virtualEnvRelativePath = '.local/share/virtualenvs';
+    }
+    const resolvedPath = path.join(os.homedir(), virtualEnvRelativePath);
+    core.debug(`global cache directory path is ${resolvedPath}`);
+
+    return [resolvedPath];
+  }
+
+  protected async computeKeys() {
+    const hash = await glob.hashFiles(this.patterns);
+    const primaryKey = `${this.CACHE_KEY_PREFIX}-${process.env['RUNNER_OS']}-python-${this.pythonVersion}-${this.packageManager}-${hash}`;
+    const restoreKey = undefined;
+    return {
+      primaryKey,
+      restoreKey
+    };
+  }
+}
+
+export default PipenvCache;