Support: Add a cache pruning policy parser.

The idea is that the policy string fully specifies the policy and is portable
between clients.

Differential Revision: https://reviews.llvm.org/D31020

llvm-svn: 297927
diff --git a/llvm/unittests/Support/CachePruningTest.cpp b/llvm/unittests/Support/CachePruningTest.cpp
new file mode 100644
index 0000000..04ac0d0
--- /dev/null
+++ b/llvm/unittests/Support/CachePruningTest.cpp
@@ -0,0 +1,71 @@
+//===- CachePruningTest.cpp -----------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/CachePruning.h"
+#include "llvm/Support/Error.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+TEST(CachePruningPolicyParser, Empty) {
+  auto P = parseCachePruningPolicy("");
+  ASSERT_TRUE(bool(P));
+  EXPECT_EQ(std::chrono::seconds(1200), P->Interval);
+  EXPECT_EQ(std::chrono::hours(7 * 24), P->Expiration);
+  EXPECT_EQ(75u, P->PercentageOfAvailableSpace);
+}
+
+TEST(CachePruningPolicyParser, Interval) {
+  auto P = parseCachePruningPolicy("prune_interval=1s");
+  ASSERT_TRUE(bool(P));
+  EXPECT_EQ(std::chrono::seconds(1), P->Interval);
+  P = parseCachePruningPolicy("prune_interval=2m");
+  ASSERT_TRUE(bool(P));
+  EXPECT_EQ(std::chrono::minutes(2), P->Interval);
+  P = parseCachePruningPolicy("prune_interval=3h");
+  ASSERT_TRUE(bool(P));
+  EXPECT_EQ(std::chrono::hours(3), P->Interval);
+}
+
+TEST(CachePruningPolicyParser, Expiration) {
+  auto P = parseCachePruningPolicy("prune_after=1s");
+  ASSERT_TRUE(bool(P));
+  EXPECT_EQ(std::chrono::seconds(1), P->Expiration);
+}
+
+TEST(CachePruningPolicyParser, PercentageOfAvailableSpace) {
+  auto P = parseCachePruningPolicy("cache_size=100%");
+  ASSERT_TRUE(bool(P));
+  EXPECT_EQ(100u, P->PercentageOfAvailableSpace);
+}
+
+TEST(CachePruningPolicyParser, Multiple) {
+  auto P = parseCachePruningPolicy("prune_after=1s:cache_size=50%");
+  ASSERT_TRUE(bool(P));
+  EXPECT_EQ(std::chrono::seconds(1200), P->Interval);
+  EXPECT_EQ(std::chrono::seconds(1), P->Expiration);
+  EXPECT_EQ(50u, P->PercentageOfAvailableSpace);
+}
+
+TEST(CachePruningPolicyParser, Errors) {
+  EXPECT_EQ("Duration must not be empty",
+            toString(parseCachePruningPolicy("prune_interval=").takeError()));
+  EXPECT_EQ("'foo' not an integer",
+            toString(parseCachePruningPolicy("prune_interval=foos").takeError()));
+  EXPECT_EQ("'24x' must end with one of 's', 'm' or 'h'",
+            toString(parseCachePruningPolicy("prune_interval=24x").takeError()));
+  EXPECT_EQ("'foo' must be a percentage",
+            toString(parseCachePruningPolicy("cache_size=foo").takeError()));
+  EXPECT_EQ("'foo' not an integer",
+            toString(parseCachePruningPolicy("cache_size=foo%").takeError()));
+  EXPECT_EQ("'101' must be between 0 and 100",
+            toString(parseCachePruningPolicy("cache_size=101%").takeError()));
+  EXPECT_EQ("Unknown key: 'foo'",
+            toString(parseCachePruningPolicy("foo=bar").takeError()));
+}