disk_reader

1. Overview

The disk_reader.cpp file provides bounded random-access reads over block devices and disk-image files.

This is an implementation file. It contains executable logic for the subsystem, including parsing, I/O, validation, recovery flow, or graphical behavior declared by the corresponding interface.

Its paired source or interface file is disk_reader.hpp.

Primary responsibilities:

  • Open a source in read-only mode
  • Read exact byte ranges
  • Report source size and read errors
  • Provide a common reader abstraction to filesystem parsers

2. File Identity and Scope

  • Source path: src/disk_reader.cpp
  • Language: C++
  • File role: implementation file
  • Physical lines: 134
  • Non-empty lines: 110
  • SHA-256: e1c7f07bce633cc564c6870dd580de30e094f8d00a5b3d5b27917c566ebdec72

The declarations in this file use the global namespace.

3. Dependencies

3.1 Project Headers

  • disk_reader.hpp
  • i18n.hpp
  • fcntl.h
  • unistd.h

3.2 Standard and External Headers

  • cerrno
  • cstring
  • sys/stat.h
  • sys/types.h
  • linux/fs.h
  • sys/ioctl.h

These dependencies define the file’s compile-time integration with the recovery engine, GTK interface, on-disk format decoders, operating-system services, or C++ standard library.

4. Declared Types

No class, structure, or enumeration definition is declared directly in this file.

5. Constants and Configuration Values

No preprocessor or compile-time constants were detected as top-level declarations in this file.

6. Data Members and Persistent State

No class data members are declared directly in this file, or the file primarily implements methods declared elsewhere.

7. API and Function Inventory

The following callable interfaces or definitions were detected:

  • DiskReader::DiskReader(): fd_(-1),is_block_device_(false),size_(0),logical_sector_size_(512) – Implements the operation identified by this API and updates or returns the associated state.
  • DiskReader::~DiskReader() – Destroys the object and releases resources owned by the instance.
  • void DiskReader::close() – Manages the corresponding resource lifecycle or resets internal state.
  • bool DiskReader::open_readonly(const std::string&path,std::string&error) – Manages the corresponding resource lifecycle or resets internal state.
  • bool DiskReader::is_open()const – Evaluates the stated condition and returns the corresponding Boolean result.
  • bool DiskReader::is_block_device()const – Evaluates the stated condition and returns the corresponding Boolean result.
  • uint64_t DiskReader::size()const – Implements the operation identified by this API and updates or returns the associated state.
  • uint32_t DiskReader::logical_sector_size()const – Implements the operation identified by this API and updates or returns the associated state.
  • const std::string&DiskReader::path()const – Implements the operation identified by this API and updates or returns the associated state.
  • bool DiskReader::read_at(uint64_t offset,void*buffer,size_t len) – Reads or derives the requested information and returns or stores the decoded result.
  • std::vector<std::byte> DiskReader::read_block(uint64_t offset,size_t len) – Reads or derives the requested information and returns or stores the decoded result.

8. Operational Flow

The subsystem represented by this file normally participates in the following flow:

  1. Open a source in read-only mode.
  2. Read exact byte ranges.
  3. Report source size and read errors.
  4. Provide a common reader abstraction to filesystem parsers.
  5. Expose or execute the detected APIs: DiskReader, ~DiskReader, close, open_readonly, is_open, is_block_device, size, logical_sector_size, path, read_at, read_block.
  6. Return explicit results, progress data, recovered records, or diagnostics to the calling layer.

9. Validation and Error Handling

  • Errors are propagated through Boolean results, error strings, logs, exceptions, or status records depending on the API.
  • Byte offsets, sizes and lengths must be validated before arithmetic and before every read to avoid overflow and out-of-bounds access.
  • Input and output paths require existence checks, permission handling and safe destination construction.

10. Runtime, Concurrency, and Resource Management

  • I/O: filesystem and raw-source operations can fail partially and must preserve exact byte counts and diagnostic context.
  • File descriptors and streams must be closed on success, cancellation and error paths.

11. Security and Data-Recovery Considerations

  • Recovery code should prefer read-only source access and avoid writing to the original damaged medium.
  • Raw devices and image files are treated as untrusted binary input; every offset and length must remain bounded by the source size.

12. Implementation Considerations

  • The implementation should remain aligned with declarations in the paired header and preserve documented return-value semantics.
  • Large-device arithmetic uses 64-bit values; additions and multiplications should be checked before use as offsets or allocation sizes.

13. Integration with the Recovery Pipeline

  • The file belongs to the source-discovery, parsing or support layer.
  • Its results feed scanner, recovery or reporting modules through shared models.
  • The API should remain deterministic so higher layers can combine results safely.

14. Licensing and Provenance

No explicit copyright or software-license statement was detected in the opening section of this individual file. Distribution terms should therefore be verified against the project-level license and repository metadata.

The SHA-256 value in this document can be used to associate the generated documentation with the exact source version analyzed.

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