Merge pull request #33065 from petermattis/backport2.1-33063

release-2.1: c-deps: fix an infinite loop in MVCCScan

c-deps/libroach/CMakeLists.txt

@@ -91,6 +91,7 @@ enable_testing()
 # List of tests to build and run. Tests in `ccl/` are linked against roachccl, all others
 # are linked against roach only.
 set(tests
+  chunked_buffer_test.cc
   db_test.cc
   encoding_test.cc
   file_registry_test.cc

c-deps/libroach/chunked_buffer.cc

@@ -49,8 +49,12 @@ void chunkedBuffer::Clear() {
 // indicate that the required size of this buffer will soon be
 // len+next_size_hint, to prevent excessive resize operations.
 void chunkedBuffer::put(const char* data, int len, int next_size_hint) {
-  const int avail = bufs_.empty() ? 0 : (bufs_.back().len - (buf_ptr_ - bufs_.back().data));
-  if (len > avail) {
+  for (;;) {
+    const size_t avail = bufs_.empty() ? 0 : (bufs_.back().len - (buf_ptr_ - bufs_.back().data));
+    if (len <= avail) {
+      break;
+    }
+
     // If it's bigger than the last buf's capacity, we fill the last buf,
     // allocate a new one, and write the remainder to the new one.  Our new
     // buf's size will be the next power of two past the size of the last buf
@@ -59,8 +63,12 @@ void chunkedBuffer::put(const char* data, int len, int next_size_hint) {
     data += avail;
     len -= avail;
 
+    const int max_size = 128 << 20; // 128 MB
     int new_size = bufs_.empty() ? 16 : bufs_.back().len * 2;
-    for (; new_size < len + next_size_hint; new_size *= 2) {
+    for (; new_size < len + next_size_hint && new_size < max_size; new_size *= 2) {
+    }
+    if (new_size > max_size) {
+      new_size = max_size;
     }
 
     DBSlice new_buf;

c-deps/libroach/chunked_buffer_test.cc

@@ -0,0 +1,40 @@
+// Copyright 2018 The Cockroach Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied.  See the License for the specific language governing
+// permissions and limitations under the License.
+
+#include <gtest/gtest.h>
+#include "chunked_buffer.h"
+
+// Verify we can a chunked buffer can hold more than 2GB of data when
+// writing in pieces that are smaller than the maximum chunk size (128
+// MB). See #32896.
+TEST(ChunkedBuffer, PutSmall) {
+  const std::string data(1 << 20, '.'); // 1 MB
+  const int64_t total = 3LL << 30;      // 3 GB
+  cockroach::chunkedBuffer buf;
+  for (int64_t sum = 0; sum < total; sum += data.size()) {
+    buf.Put(data, data);
+  }
+}
+
+// Verify we can a chunked buffer can hold more than 2GB of data when
+// writing in pieces that are larger than the maximum chunk size (128
+// MB). See #32896.
+TEST(ChunkedBuffer, PutLarge) {
+  const std::string data(256 << 20, '.'); // 256 MB
+  const int64_t total = 3LL << 30;        // 3 GB
+  cockroach::chunkedBuffer buf;
+  for (int64_t sum = 0; sum < total; sum += data.size()) {
+    buf.Put(data, data);
+  }
+}