Replace GrTHash with SkTDynamicHash

Mike: SkTDynamicHash changes
Brian: Ganesh changes

This removes three instances of GrTHash leaving the ones in GrTextStrike.h

R=mtklein@google.com, bsalomon@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/402693003

1 files changed, 58 insertions, 0 deletions

diff --git a/src/gpu/GrBinHashKey.h b/src/gpu/GrBinHashKey.h
index 585a1a1c01..06ff931808 100644
--- a/src/gpu/GrBinHashKey.h
+++ b/src/gpu/GrBinHashKey.h
@@ -10,9 +10,67 @@
 #ifndef GrBinHashKey_DEFINED
 #define GrBinHashKey_DEFINED
 
+#include "SkChecksum.h"
 #include "GrTypes.h"
 
 /**
+ *  GrMurmur3HashKey is a hash key class that can take a data chunk of any predetermined
+ *  length. It uses the Murmur3 hash function. It is intended to be used with
+ *  SkTDynamicHash (where GrBinHashKey is for GrTHashTable).
+ */
+template<size_t KEY_SIZE_IN_BYTES>
+class GrMurmur3HashKey {
+public:
+    GrMurmur3HashKey() {
+        this->reset();
+    }
+
+    void reset() {
+        fHash = 0;
+#ifdef SK_DEBUG
+        fIsValid = false;
+#endif
+    }
+
+    void setKeyData(const uint32_t* data) {
+        SK_COMPILE_ASSERT(KEY_SIZE_IN_BYTES % 4 == 0, key_size_mismatch);
+        memcpy(fData, data, KEY_SIZE_IN_BYTES);
+
+        fHash = SkChecksum::Murmur3(fData, KEY_SIZE_IN_BYTES);
+#ifdef SK_DEBUG
+        fIsValid = true;
+#endif
+    }
+
+    bool operator==(const GrMurmur3HashKey& other) const {
+        if (fHash != other.fHash) {
+            return false;
+        }
+
+        return !memcmp(fData, other.fData, KEY_SIZE_IN_BYTES);
+    }
+
+    uint32_t getHash() const {
+        SkASSERT(fIsValid);
+        return fHash;
+    }
+
+    const uint8_t* getData() const {
+        SkASSERT(fIsValid);
+        return reinterpret_cast<const uint8_t*>(fData);
+    }
+
+private:
+    uint32_t fHash;
+    uint32_t fData[KEY_SIZE_IN_BYTES / sizeof(uint32_t)];  // Buffer for key storage.
+
+#ifdef SK_DEBUG
+public:
+    bool                fIsValid;
+#endif
+};
+
+/**
  *  GrBinHashKey is a hash key class that can take a data chunk of any predetermined
  *  length. The hash function used is the One-at-a-Time Hash
  *  (http://burtleburtle.net/bob/hash/doobs.html).