1    :  // Copyright 2015 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  
  15    :  #ifndef SYZYGY_REFINERY_CORE_BIT_SOURCE_H_
  16    :  #define SYZYGY_REFINERY_CORE_BIT_SOURCE_H_
  17    :  
  18    :  #include "base/logging.h"
  19    :  #include "base/macros.h"
  20    :  #include "syzygy/refinery/core/address.h"
  21    :  
  22    :  namespace refinery {
  23    :  
  24    :  // An interface to the contents of an address space. Typically, the address
  25    :  // space's contents are only partially known. Access to the memory is
  26    :  // copy-based to avoid any alignment issues.
  27    :  class BitSource {
  28    :   public:
  29  E :    virtual ~BitSource() = 0 {}
  30    :  
  31    :    // Retrieves all bytes from a range.
  32    :    // @pre @p range must be a valid range.
  33    :    // @param range the requested range.
  34    :    // @param data_ptr a buffer of size at least that of @p range. On success,
  35    :    //    contains the returned data.
  36    :    // @returns true iff the full contents of @p range are available.
  37    :    virtual bool GetAll(const AddressRange& range, void* data_ptr) = 0;
  38    :  
  39    :    // Determine how many bytes are available from the head of a range and
  40    :    // optionally retrieve them.
  41    :    // @pre @p range must be a valid range.
  42    :    // @param range the requested range.
  43    :    // @param data_cnt on success, contains the number of bytes returned from the
  44    :    //   head of @p range.
  45    :    // @param data_ptr a buffer of size at least that of @p range or nullptr. On
  46    :    //   success, a valid buffer contains the returned data.
  47    :    // @returns true iff some data is available from the head of @p range.
  48    :    virtual bool GetFrom(const AddressRange& range,
  49    :                         size_t* data_cnt,
  50    :                         void* data_ptr) = 0;
  51    :  
  52    :    // Determines whether any bytes are available for a range.
  53    :    // @param range the range.
  54    :    // @returns true iff some data is available in the desired range.
  55    :    virtual bool HasSome(const AddressRange& range) = 0;
  56    :  };
  57    :  
  58    :  }  // namespace refinery
  59    :  
  60    :  #endif  // SYZYGY_REFINERY_CORE_BIT_SOURCE_H_