Allow Cord to store chunked checksums

PiperOrigin-RevId: 494587777
Change-Id: I41504edca6fcf750d52602fa84a33bc7fe5fbb48

4 files changed, 32 insertions, 20 deletions

diff --git a/absl/strings/internal/cord_rep_crc.cc b/absl/strings/internal/cord_rep_crc.cc
index 7d7273ef..dbe54cc4 100644
--- a/absl/strings/internal/cord_rep_crc.cc
+++ b/absl/strings/internal/cord_rep_crc.cc
@@ -16,6 +16,7 @@
 
 #include <cassert>
 #include <cstdint>
+#include <utility>
 
 #include "absl/base/config.h"
 #include "absl/strings/internal/cord_internal.h"
@@ -24,10 +25,10 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace cord_internal {
 
-CordRepCrc* CordRepCrc::New(CordRep* child, uint32_t crc) {
+CordRepCrc* CordRepCrc::New(CordRep* child, crc_internal::CrcCordState state) {
   if (child != nullptr && child->IsCrc()) {
     if (child->refcount.IsOne()) {
-      child->crc()->crc = crc;
+      child->crc()->crc_cord_state = std::move(state);
       return child->crc();
     }
     CordRep* old = child;
@@ -39,7 +40,7 @@ CordRepCrc* CordRepCrc::New(CordRep* child, uint32_t crc) {
   new_cordrep->length = child != nullptr ? child->length : 0;
   new_cordrep->tag = cord_internal::CRC;
   new_cordrep->child = child;
-  new_cordrep->crc = crc;
+  new_cordrep->crc_cord_state = std::move(state);
   return new_cordrep;
 }
 
diff --git a/absl/strings/internal/cord_rep_crc.h b/absl/strings/internal/cord_rep_crc.h
index 455a1127..379d7a60 100644
--- a/absl/strings/internal/cord_rep_crc.h
+++ b/absl/strings/internal/cord_rep_crc.h
@@ -20,6 +20,7 @@
 
 #include "absl/base/config.h"
 #include "absl/base/optimization.h"
+#include "absl/crc/internal/crc_cord_state.h"
 #include "absl/strings/internal/cord_internal.h"
 
 namespace absl {
@@ -34,14 +35,14 @@ namespace cord_internal {
 // the contained checksum is the user's responsibility.
 struct CordRepCrc : public CordRep {
   CordRep* child;
-  uint32_t crc;
+  absl::crc_internal::CrcCordState crc_cord_state;
 
   // Consumes `child` and returns a CordRepCrc prefixed tree containing `child`.
   // If the specified `child` is itself a CordRepCrc node, then this method
-  // either replaces the existing node, or directly updates the crc value in it
+  // either replaces the existing node, or directly updates the crc state in it
   // depending on the node being shared or not, i.e.: refcount.IsOne().
   // `child` must only be null if the Cord is empty. Never returns null.
-  static CordRepCrc* New(CordRep* child, uint32_t crc);
+  static CordRepCrc* New(CordRep* child, crc_internal::CrcCordState state);
 
   // Destroys (deletes) the provided node. `node` must not be null.
   static void Destroy(CordRepCrc* node);
diff --git a/absl/strings/internal/cord_rep_crc_test.cc b/absl/strings/internal/cord_rep_crc_test.cc
index 42a9110b..3d27c33c 100644
--- a/absl/strings/internal/cord_rep_crc_test.cc
+++ b/absl/strings/internal/cord_rep_crc_test.cc
@@ -17,6 +17,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "absl/base/config.h"
+#include "absl/crc/internal/crc_cord_state.h"
 #include "absl/strings/internal/cord_internal.h"
 #include "absl/strings/internal/cord_rep_test_util.h"
 
@@ -38,33 +39,40 @@ TEST(CordRepCrc, RemoveCrcWithNullptr) {
 
 #endif  // !NDEBUG && GTEST_HAS_DEATH_TEST
 
+absl::crc_internal::CrcCordState MakeCrcCordState(uint32_t crc) {
+  crc_internal::CrcCordState state;
+  state.mutable_rep()->prefix_crc.push_back(
+      crc_internal::CrcCordState::PrefixCrc(42, crc32c_t{crc}));
+  return state;
+}
+
 TEST(CordRepCrc, NewDestroy) {
   CordRep* rep = cordrep_testing::MakeFlat("Hello world");
-  CordRepCrc* crc = CordRepCrc::New(rep, 12345);
+  CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
   EXPECT_TRUE(crc->refcount.IsOne());
   EXPECT_THAT(crc->child, Eq(rep));
-  EXPECT_THAT(crc->crc, Eq(12345u));
+  EXPECT_THAT(crc->crc_cord_state.Checksum(), Eq(crc32c_t{12345u}));
   EXPECT_TRUE(rep->refcount.IsOne());
   CordRepCrc::Destroy(crc);
 }
 
 TEST(CordRepCrc, NewExistingCrcNotShared) {
   CordRep* rep = cordrep_testing::MakeFlat("Hello world");
-  CordRepCrc* crc = CordRepCrc::New(rep, 12345);
-  CordRepCrc* new_crc = CordRepCrc::New(crc, 54321);
+  CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
+  CordRepCrc* new_crc = CordRepCrc::New(crc, MakeCrcCordState(54321));
   EXPECT_THAT(new_crc, Eq(crc));
   EXPECT_TRUE(new_crc->refcount.IsOne());
   EXPECT_THAT(new_crc->child, Eq(rep));
-  EXPECT_THAT(new_crc->crc, Eq(54321u));
+  EXPECT_THAT(new_crc->crc_cord_state.Checksum(), Eq(crc32c_t{54321u}));
   EXPECT_TRUE(rep->refcount.IsOne());
   CordRepCrc::Destroy(new_crc);
 }
 
 TEST(CordRepCrc, NewExistingCrcShared) {
   CordRep* rep = cordrep_testing::MakeFlat("Hello world");
-  CordRepCrc* crc = CordRepCrc::New(rep, 12345);
+  CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
   CordRep::Ref(crc);
-  CordRepCrc* new_crc = CordRepCrc::New(crc, 54321);
+  CordRepCrc* new_crc = CordRepCrc::New(crc, MakeCrcCordState(54321));
 
   EXPECT_THAT(new_crc, Ne(crc));
   EXPECT_TRUE(new_crc->refcount.IsOne());
@@ -72,19 +80,19 @@ TEST(CordRepCrc, NewExistingCrcShared) {
   EXPECT_FALSE(rep->refcount.IsOne());
   EXPECT_THAT(crc->child, Eq(rep));
   EXPECT_THAT(new_crc->child, Eq(rep));
-  EXPECT_THAT(crc->crc, Eq(12345u));
-  EXPECT_THAT(new_crc->crc, Eq(54321u));
+  EXPECT_THAT(crc->crc_cord_state.Checksum(), Eq(crc32c_t{12345u}));
+  EXPECT_THAT(new_crc->crc_cord_state.Checksum(), Eq(crc32c_t{54321u}));
 
   CordRep::Unref(crc);
   CordRep::Unref(new_crc);
 }
 
 TEST(CordRepCrc, NewEmpty) {
-  CordRepCrc* crc = CordRepCrc::New(nullptr, 12345);
+  CordRepCrc* crc = CordRepCrc::New(nullptr, MakeCrcCordState(12345));
   EXPECT_TRUE(crc->refcount.IsOne());
   EXPECT_THAT(crc->child, IsNull());
   EXPECT_THAT(crc->length, Eq(0u));
-  EXPECT_THAT(crc->crc, Eq(12345u));
+  EXPECT_THAT(crc->crc_cord_state.Checksum(), Eq(crc32c_t{12345u}));
   EXPECT_TRUE(crc->refcount.IsOne());
   CordRepCrc::Destroy(crc);
 }
@@ -98,7 +106,7 @@ TEST(CordRepCrc, RemoveCrcNotCrc) {
 
 TEST(CordRepCrc, RemoveCrcNotShared) {
   CordRep* rep = cordrep_testing::MakeFlat("Hello world");
-  CordRepCrc* crc = CordRepCrc::New(rep, 12345);
+  CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
   CordRep* nocrc = RemoveCrcNode(crc);
   EXPECT_THAT(nocrc, Eq(rep));
   EXPECT_TRUE(rep->refcount.IsOne());
@@ -107,7 +115,7 @@ TEST(CordRepCrc, RemoveCrcNotShared) {
 
 TEST(CordRepCrc, RemoveCrcShared) {
   CordRep* rep = cordrep_testing::MakeFlat("Hello world");
-  CordRepCrc* crc = CordRepCrc::New(rep, 12345);
+  CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
   CordRep::Ref(crc);
   CordRep* nocrc = RemoveCrcNode(crc);
   EXPECT_THAT(nocrc, Eq(rep));
diff --git a/absl/strings/internal/cordz_info_statistics_test.cc b/absl/strings/internal/cordz_info_statistics_test.cc
index 6d6feb52..53d2f2ea 100644
--- a/absl/strings/internal/cordz_info_statistics_test.cc
+++ b/absl/strings/internal/cordz_info_statistics_test.cc
@@ -19,6 +19,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "absl/base/config.h"
+#include "absl/crc/internal/crc_cord_state.h"
 #include "absl/strings/cord.h"
 #include "absl/strings/internal/cord_internal.h"
 #include "absl/strings/internal/cord_rep_btree.h"
@@ -451,7 +452,8 @@ TEST(CordzInfoStatisticsTest, BtreeNodeShared) {
 TEST(CordzInfoStatisticsTest, Crc) {
   RefHelper ref;
   auto* left = Flat(1000);
-  auto* crc = ref.NeedsUnref(CordRepCrc::New(left, 12345));
+  auto* crc =
+      ref.NeedsUnref(CordRepCrc::New(left, crc_internal::CrcCordState()));
 
   CordzStatistics expected;
   expected.size = left->length;