| // Copyright 2018 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef LIB_INSPECT_CPP_VMO_LIMITS_H_ |
| #define LIB_INSPECT_CPP_VMO_LIMITS_H_ |
| |
| #include <zircon/types.h> |
| |
| #include <climits> |
| #include <cstdint> |
| |
| namespace inspect { |
| namespace internal { |
| |
| // The size for order 0. |
| constexpr size_t kMinOrderShift = 4; |
| constexpr size_t kMinOrderSize = 1 << kMinOrderShift; // 16 bytes |
| |
| // The total number of orders in the buddy allocator. |
| constexpr size_t kNumOrders = 8; |
| |
| // `kEmptyStringSlotIndex` a special value semantically representing |
| // an empty string in a string array. It is used in place of a string reference |
| // index, and is read as `""`. |
| constexpr uint64_t kEmptyStringSlotIndex = 0; |
| |
| // The size of the maximum order. |
| constexpr size_t kMaxOrderShift = kMinOrderShift + kNumOrders - 1; |
| constexpr size_t kMaxOrderSize = 1 << kMaxOrderShift; |
| |
| // The minimum size for the inspection VMO. |
| constexpr size_t kMinVmoSize = 4096; |
| static_assert(kMinVmoSize >= kMaxOrderSize, "Maximum order size must fit in the smallest VMO"); |
| |
| // The maximum size for the inspection VMO. |
| constexpr size_t kMaxVmoSize = 256L * 1024L * 1024L; |
| static_assert(kMaxVmoSize >= kMinVmoSize, |
| "Maximum VMO size must be greater or equal to minimum VMO size"); |
| |
| // The magic number for verifying the VMO format. |
| constexpr char kMagicNumber[5] = "INSP"; |
| |
| // The version of Inspect Format we support. |
| constexpr size_t kVersion = 2; |
| |
| constexpr size_t kVmoFrozen = 0xFFFFFFFFFFFFFFFE; |
| |
| // The order of Inspect VMO header. |
| constexpr size_t kVmoHeaderOrder = 1; |
| |
| // The size of Inspect VMO header block. |
| constexpr size_t kVmoHeaderBlockSize = kMinOrderSize * 2; |
| |
| template <typename T> |
| constexpr size_t OrderToSize(T order) { |
| return kMinOrderSize << order; |
| } |
| |
| constexpr size_t IndexForOffset(size_t offset) { return offset / kMinOrderSize; } |
| |
| } // namespace internal |
| } // namespace inspect |
| |
| #endif // LIB_INSPECT_CPP_VMO_LIMITS_H_ |