Add validation caching interface.

src/trusted/validator/x86/32/ncvalidate.c

Index: src/trusted/validator/x86/32/ncvalidate.c
diff --git a/src/trusted/validator/x86/32/ncvalidate.c b/src/trusted/validator/x86/32/ncvalidate.c
index 5b00fc6540bd7a98e7bc7a028dbdd15577820033..de6233c5515c0587852dc236766d985289d143fc 100644
--- a/src/trusted/validator/x86/32/ncvalidate.c
+++ b/src/trusted/validator/x86/32/ncvalidate.c
@@ -9,6 +9,8 @@
 #include "native_client/src/trusted/validator/ncvalidate.h"
 #include "native_client/src/trusted/validator/x86/ncval_seg_sfi/ncvalidate.h"
 #include "native_client/src/trusted/validator/x86/ncval_seg_sfi/ncvalidate_detailed.h"
+/* TODO(ncbray) is there a better way to access validation stats? */

[Mark Seaborn, 2012/03/01 00:26:20]

You could add a getter function

[Nick Bray (chromium), 2012/03/01 01:25:16]

Done.

+#include "native_client/src/trusted/validator/x86/ncval_seg_sfi/ncvalidate_internaltypes.h"
 #include <assert.h>
 
 /* Be sure the correct compile flags are defined for this. */
@@ -25,14 +27,43 @@ static NaClValidationStatus NCApplyValidatorSilently_x86_32(
     uint8_t *data,
     size_t size,
     int bundle_size,
-    NaClCPUFeaturesX86 *cpu_features) {
+    NaClCPUFeaturesX86 *cpu_features,
+    NaClValidationCache *cache) {
   struct NCValidatorState *vstate;
   int validator_result = 0;
 

[Mark Seaborn, 2012/03/01 00:26:20]

remove empty line, keep variables block together?

[Nick Bray (chromium), 2012/03/01 01:25:16]

Done.

+  void *query = NULL;
+
+  if (cache != NULL)
+    query = cache->CreateQuery(cache->context);
+
+  if (query != NULL) {
+    const char validator_id[] = "x86-32";
+    cache->AddData(query, (uint8_t *) validator_id, sizeof(validator_id));
+    cache->AddData(query, (uint8_t *) cpu_features, sizeof(NaClCPUFeaturesX86));

[Mark Seaborn, 2012/03/01 00:26:20]

sizeof(*cpu_features) reduces the risk of skew

[Nick Bray (chromium), 2012/03/01 01:25:16]

Done.

+    cache->AddData(query, data, size);
+    if (cache->DoQuery(query)) {
+      cache->DestroyQuery(query);
+      return NaClValidationSucceeded;
+    }
+  }
+
   vstate = NCValidateInit(guest_addr, size, bundle_size, cpu_features);
-  if (vstate == NULL) return NaClValidationFailedOutOfMemory;
+  if (vstate == NULL) {
+    if (query != NULL)
+      cache->DestroyQuery(query);
+    return NaClValidationFailedOutOfMemory;
+  }
   NCValidateSegment(data, guest_addr, size, vstate);
   validator_result = NCValidateFinish(vstate);
+
+  if (query != NULL) {
+    /* Don't cache the result if the code is modified. */
+    if (validator_result == 0 && vstate->stats.didstubout == 0)
+      cache->SetValidates(query);
+    cache->DestroyQuery(query);
+  }
+
   NCValidateFreeState(&vstate);
   return (validator_result == 0)
       ? NaClValidationSucceeded : NaClValidationFailed;
@@ -62,7 +93,8 @@ NaClValidationStatus NACL_SUBARCH_NAME(ApplyValidator, NACL_TARGET_ARCH, 32) (
     uint8_t *data,
     size_t size,
     int bundle_size,
-    NaClCPUFeaturesX86 *cpu_features) {
+    NaClCPUFeaturesX86 *cpu_features,
+    NaClValidationCache *cache) {
   NaClValidationStatus status = NaClValidationFailedNotImplemented;
   assert(NACL_SB_DEFAULT == sb_kind);
   if (bundle_size == 16 || bundle_size == 32) {
@@ -71,7 +103,7 @@ NaClValidationStatus NACL_SUBARCH_NAME(ApplyValidator, NACL_TARGET_ARCH, 32) (
     switch (kind) {
       case NaClApplyCodeValidation:
         status = NCApplyValidatorSilently_x86_32(
-            guest_addr, data, size, bundle_size, cpu_features);
+            guest_addr, data, size, bundle_size, cpu_features, cache);
         break;
       case NaClApplyValidationDoStubout:
         status = NCApplyValidatorStubout_x86_32(