Spin off SkTHashTable, SkTHashMap, SkTHashSet

SkTHashTable is very similar to SkTDynamicHash, except it's generalized to support non-pointer value types.

It doesn't support remove(), just to keep things simple (it's not hard to add).
Instead of an iterator, it has foreach(), again, to keep things simple.

SkTHashMap<K,V> and SkTHashSet<T> build a friendlier experience on top of SkTHashTable.

BUG=skia:

Review URL: https://codereview.chromium.org/925613002

1 files changed, 57 insertions, 0 deletions

diff --git a/tests/HashTest.cpp b/tests/HashTest.cpp
new file mode 100644
index 0000000000..24032a5ec5
--- /dev/null
+++ b/tests/HashTest.cpp
@@ -0,0 +1,57 @@
+#include "SkChecksum.h"
+#include "SkString.h"
+#include "SkTHash.h"
+#include "Test.h"
+
+namespace { uint32_t hash_int(int k) { return SkChecksum::Mix(k); } }
+
+static void set_negative_key(int key, double* d) { *d = -key; }
+
+DEF_TEST(HashMap, r) {
+    SkTHashMap<int, double, hash_int> map;
+
+    map.set(3, 4.0);
+    REPORTER_ASSERT(r, map.count() == 1);
+
+    double* found = map.find(3);
+    REPORTER_ASSERT(r, found);
+    REPORTER_ASSERT(r, *found == 4.0);
+
+    map.foreach(set_negative_key);
+    found = map.find(3);
+    REPORTER_ASSERT(r, found);
+    REPORTER_ASSERT(r, *found == -3.0);
+
+    REPORTER_ASSERT(r, !map.find(2));
+
+    const int N = 20;
+
+    for (int i = 0; i < N; i++) {
+        map.set(i, 2.0*i);
+    }
+    for (int i = 0; i < N; i++) {
+        double* found = map.find(i);;
+        REPORTER_ASSERT(r, found);
+        REPORTER_ASSERT(r, *found == i*2.0);
+    }
+    for (int i = N; i < 2*N; i++) {
+        REPORTER_ASSERT(r, !map.find(i));
+    }
+
+    REPORTER_ASSERT(r, map.count() == N);
+}
+
+namespace { uint32_t hash_string(SkString s) { return s.size(); } }
+
+DEF_TEST(HashSet, r) {
+    SkTHashSet<SkString, hash_string> set;
+
+    set.add(SkString("Hello"));
+    set.add(SkString("World"));
+
+    REPORTER_ASSERT(r, set.count() == 2);
+
+    REPORTER_ASSERT(r, set.contains(SkString("Hello")));
+    REPORTER_ASSERT(r, set.contains(SkString("World")));
+    REPORTER_ASSERT(r, !set.contains(SkString("Goodbye")));
+}