Add validation caching interface.

src/trusted/validator/x86/64/ncvalidate.c

Index: src/trusted/validator/x86/64/ncvalidate.c
diff --git a/src/trusted/validator/x86/64/ncvalidate.c b/src/trusted/validator/x86/64/ncvalidate.c
index e07cc68095103f8a3707d2c297872efa1a4d6a7b..ad3f8e40635a02fcaa773dfcac1b9bcb5662519d 100644
--- a/src/trusted/validator/x86/64/ncvalidate.c
+++ b/src/trusted/validator/x86/64/ncvalidate.c
@@ -6,9 +6,9 @@
 
 /* Implement the ApplyValidator API for the x86-64 architecture. */
 #include <assert.h>
-#include "native_client/src/trusted/validator/ncvalidate.h"
-
 #include "native_client/src/shared/platform/nacl_log.h"
+#include "native_client/src/trusted/validator/ncvalidate.h"
+#include "native_client/src/trusted/validator/validation_cache.h"
 #include "native_client/src/trusted/validator/x86/ncval_reg_sfi/ncvalidate_iter.h"
 
 /* Be sure the correct compile flags are defined for this. */
@@ -33,32 +33,53 @@ NaClValidationStatus NaClValidatorSetup_x86_64(
       : NaClValidationSucceeded;     /* or at least to this point! */
 }
 
-Bool NaClSegmentValidate_x86_64(
-    uintptr_t guest_addr,
-    uint8_t *data,
-    size_t size,
-    struct NaClValidatorState* vstate) {
-  Bool is_ok;
-  NaClValidateSegment(data, guest_addr, size, vstate);
-  is_ok = NaClValidatesOk(vstate);
-  NaClValidatorStateDestroy(vstate);
-  return is_ok;
-}
-
 static NaClValidationStatus NaClApplyValidatorSilently_x86_64(
     uintptr_t guest_addr,
     uint8_t *data,
     size_t size,
     int bundle_size,
-    NaClCPUFeaturesX86 *cpu_features) {
+    NaClCPUFeaturesX86 *cpu_features,
+    struct NaClValidationCache *cache) {
   struct NaClValidatorState *vstate;
-  NaClValidationStatus status =
+  NaClValidationStatus status;
+  void *query = NULL;
+
+  if (cache != NULL)
+    query = cache->CreateQuery(cache->handle);
+
+  if (query != NULL) {
+    const char validator_id[] = "x86-64";
+    cache->AddData(query, (uint8_t *) validator_id, sizeof(validator_id));
+    cache->AddData(query, (uint8_t *) cpu_features, sizeof(*cpu_features));
+    cache->AddData(query, data, size);
+    if (cache->QueryKnownToValidate(query)) {
+      cache->DestroyQuery(query);
+      return NaClValidationSucceeded;
+    }
+  }
+
+  status =
       NaClValidatorSetup_x86_64(guest_addr, size, bundle_size, cpu_features,
                                 &vstate);
-  if (status != NaClValidationSucceeded) return status;
+
+  if (status != NaClValidationSucceeded) {
+    if (query != NULL)
+      cache->DestroyQuery(query);
+    return status;
+  }
   NaClValidatorStateSetLogVerbosity(vstate, LOG_ERROR);
-  return NaClSegmentValidate_x86_64(guest_addr, data, size, vstate)
-      ? NaClValidationSucceeded : NaClValidationFailed;
+  NaClValidateSegment(data, guest_addr, size, vstate);
+  status =
+      NaClValidatesOk(vstate) ? NaClValidationSucceeded : NaClValidationFailed;
+
+  if (query != NULL) {
+    /* Don't cache the result if the code is modified. */
+    if (status == NaClValidationSucceeded && !NaClValidatorDidStubOut(vstate))
+      cache->SetKnownToValidate(query);
+    cache->DestroyQuery(query);
+  }
+  NaClValidatorStateDestroy(vstate);
+  return status;
 }
 
 NaClValidationStatus NaClApplyValidatorStubout_x86_64(
@@ -73,7 +94,8 @@ NaClValidationStatus NaClApplyValidatorStubout_x86_64(
                                 &vstate);
   if (status != NaClValidationSucceeded) return status;
   NaClValidatorStateSetDoStubOut(vstate, TRUE);
-  NaClSegmentValidate_x86_64(guest_addr, data, size, vstate);
+  NaClValidateSegment(data, guest_addr, size, vstate);
+  NaClValidatorStateDestroy(vstate);
   return NaClValidationSucceeded;
 }
 
@@ -84,7 +106,8 @@ NaClValidationStatus NACL_SUBARCH_NAME(ApplyValidator, x86, 64) (
     uint8_t *data,
     size_t size,
     int bundle_size,
-    NaClCPUFeaturesX86 *cpu_features) {
+    NaClCPUFeaturesX86 *cpu_features,
+    struct NaClValidationCache *cache) {
   NaClValidationStatus status = NaClValidationFailedNotImplemented;
   assert(NACL_SB_DEFAULT == sb_kind);
   if (bundle_size == 16 || bundle_size == 32) {
@@ -93,7 +116,7 @@ NaClValidationStatus NACL_SUBARCH_NAME(ApplyValidator, x86, 64) (
     switch (kind) {
       case NaClApplyCodeValidation:
         status = NaClApplyValidatorSilently_x86_64(
-            guest_addr, data, size, bundle_size, cpu_features);
+            guest_addr, data, size, bundle_size, cpu_features, cache);
         break;
       case NaClApplyValidationDoStubout:
         status = NaClApplyValidatorStubout_x86_64(