Add Reallocate implementation to PyArrowMemoryPool

Change-Id: I649da045944f87571c2b84e0e3f710b93958bd2b

Author: xhochy

cpp/src/arrow/io/io-file-test.cc

@@ -291,8 +291,17 @@ class MyMemoryPool : public MemoryPool {
   }
 
   void Free(uint8_t* buffer, int64_t size) override { std::free(buffer); }
+
   Status Reallocate(int64_t old_size, int64_t new_size, uint8_t** ptr) override {
     *ptr = reinterpret_cast<uint8_t*>(std::realloc(*ptr, new_size));
+
+    if (*ptr == NULL) {
+      std::stringstream ss;
+      ss << "realloc of size " << new_size << " failed";
+      return Status::OutOfMemory(ss.str());
+    }
+
+
     return Status::OK();
   }
 

python/src/pyarrow/common.cc

@@ -47,6 +47,20 @@ class PyArrowMemoryPool : public arrow::MemoryPool {
     return Status::OK();
   }
 
+  Status Reallocate(int64_t old_size, int64_t new_size, uint8_t** ptr) override {
+    *ptr = reinterpret_cast<uint8_t*>(std::realloc(*ptr, new_size));
+
+    if (*ptr == NULL) {
+      std::stringstream ss;
+      ss << "realloc of size " << new_size << " failed";
+      return Status::OutOfMemory(ss.str());
+    }
+
+    bytes_allocated_ += new_size - old_size;
+
+    return Status::OK();
+  }
+
   int64_t bytes_allocated() const override {
     std::lock_guard<std::mutex> guard(pool_lock_);
     return bytes_allocated_;