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Pods/gRPC-C++/include/grpcpp/support/slice.h

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+//
+//
+// Copyright 2015 gRPC 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.
+//
+//
+
+#ifndef GRPCPP_SUPPORT_SLICE_H
+#define GRPCPP_SUPPORT_SLICE_H
+
+#include <grpc/slice.h>
+#include <grpcpp/support/config.h>
+#include <grpcpp/support/string_ref.h>
+
+namespace grpc {
+
+/// A wrapper around \a grpc_slice.
+///
+/// A slice represents a contiguous reference counted array of bytes.
+/// It is cheap to take references to a slice, and it is cheap to create a
+/// slice pointing to a subset of another slice.
+class Slice final {
+ public:
+  /// Construct an empty slice.
+  Slice() : slice_(grpc_empty_slice()) {}
+  /// Destructor - drops one reference.
+  ~Slice() { grpc_slice_unref(slice_); }
+
+  enum AddRef { ADD_REF };
+  /// Construct a slice from \a slice, adding a reference.
+  Slice(grpc_slice slice, AddRef) : slice_(grpc_slice_ref(slice)) {}
+
+  enum StealRef { STEAL_REF };
+  /// Construct a slice from \a slice, stealing a reference.
+  Slice(grpc_slice slice, StealRef) : slice_(slice) {}
+
+  /// Allocate a slice of specified size
+  explicit Slice(size_t len) : slice_(grpc_slice_malloc(len)) {}
+
+  /// Construct a slice from a copied buffer
+  Slice(const void* buf, size_t len)
+      : slice_(grpc_slice_from_copied_buffer(reinterpret_cast<const char*>(buf),
+                                             len)) {}
+
+  /// Construct a slice from a copied string
+  // NOLINTNEXTLINE(google-explicit-constructor)
+  Slice(const std::string& str)
+      : slice_(grpc_slice_from_copied_buffer(str.c_str(), str.length())) {}
+
+  enum StaticSlice { STATIC_SLICE };
+
+  /// Construct a slice from a static buffer
+  Slice(const void* buf, size_t len, StaticSlice)
+      : slice_(grpc_slice_from_static_buffer(reinterpret_cast<const char*>(buf),
+                                             len)) {}
+
+  /// Copy constructor, adds a reference.
+  Slice(const Slice& other) : slice_(grpc_slice_ref(other.slice_)) {}
+
+  /// Move constructor, steals a reference.
+  Slice(Slice&& other) noexcept : slice_(other.slice_) {
+    other.slice_ = grpc_empty_slice();
+  }
+
+  /// Assignment, reference count is unchanged.
+  Slice& operator=(Slice other) {
+    std::swap(slice_, other.slice_);
+    return *this;
+  }
+
+  /// Create a slice pointing at some data. Calls malloc to allocate a refcount
+  /// for the object, and arranges that destroy will be called with the
+  /// user data pointer passed in at destruction. Can be the same as buf or
+  /// different (e.g., if data is part of a larger structure that must be
+  /// destroyed when the data is no longer needed)
+  Slice(void* buf, size_t len, void (*destroy)(void*), void* user_data)
+      : slice_(grpc_slice_new_with_user_data(buf, len, destroy, user_data)) {}
+
+  /// Specialization of above for common case where buf == user_data
+  Slice(void* buf, size_t len, void (*destroy)(void*))
+      : Slice(buf, len, destroy, buf) {}
+
+  /// Similar to the above but has a destroy that also takes slice length
+  Slice(void* buf, size_t len, void (*destroy)(void*, size_t))
+      : slice_(grpc_slice_new_with_len(buf, len, destroy)) {}
+
+  /// Byte size.
+  size_t size() const { return GRPC_SLICE_LENGTH(slice_); }
+
+  /// Raw pointer to the beginning (first element) of the slice.
+  const uint8_t* begin() const { return GRPC_SLICE_START_PTR(slice_); }
+
+  /// Raw pointer to the end (one byte \em past the last element) of the slice.
+  const uint8_t* end() const { return GRPC_SLICE_END_PTR(slice_); }
+
+  /// Returns a substring of the `slice` as another slice.
+  Slice sub(size_t begin, size_t end) const {
+    return Slice(grpc_slice_sub(slice_, begin, end), STEAL_REF);
+  }
+
+  /// Raw C slice. Caller needs to call grpc_slice_unref when done.
+  grpc_slice c_slice() const { return grpc_slice_ref(slice_); }
+
+ private:
+  friend class ByteBuffer;
+
+  grpc_slice slice_;
+};
+
+inline grpc::string_ref StringRefFromSlice(const grpc_slice* slice) {
+  return grpc::string_ref(
+      reinterpret_cast<const char*>(GRPC_SLICE_START_PTR(*slice)),
+      GRPC_SLICE_LENGTH(*slice));
+}
+
+inline std::string StringFromCopiedSlice(grpc_slice slice) {
+  return std::string(reinterpret_cast<char*>(GRPC_SLICE_START_PTR(slice)),
+                     GRPC_SLICE_LENGTH(slice));
+}
+
+inline grpc_slice SliceReferencingString(const std::string& str) {
+  return grpc_slice_from_static_buffer(str.data(), str.length());
+}
+
+inline grpc_slice SliceFromCopiedString(const std::string& str) {
+  return grpc_slice_from_copied_buffer(str.data(), str.length());
+}
+
+}  // namespace grpc
+
+#endif  // GRPCPP_SUPPORT_SLICE_H