Data

Tools

Indexes

Applications

Experiments

Awesome

An open API service indexing awesome lists of open source software.

https://github.com/ascriver/mhtmlextractor

An MHTML extraction tool to decode and save components of MHTML documents as separate files with logging and CLI support.
https://github.com/ascriver/mhtmlextractor

mhtml mhtml-files python python-3

Last synced: 7 months ago
JSON representation

An MHTML extraction tool to decode and save components of MHTML documents as separate files with logging and CLI support.

Awesome Lists containing this project

README 

          
# MHTMLExtractor



`MHTMLExtractor` is a high-performance, standalone Python utility to extract files from MHTML (MIME HTML) documents. These documents are typically a snapshot of a web page and might contain images, scripts, styles, and the web page itself as a single file.



## Features



- **High Performance**: Optimized memory usage and processing speed with automatic buffer sizing

- **Dry-run Mode**: Analyze MHTML files without extracting to preview contents

- **Comprehensive Statistics**: Detailed extraction statistics and timing information

- **Type Safety**: Full type hints for better code quality and IDE support

- **Flexible Filtering**: Selectively skip extraction of certain file types (CSS, images, etc.)

- **Smart Filename Handling**: Intelligent filename generation with conflict resolution

- **Efficient Processing**: Optimized string operations and memory management

- **Progress Reporting**: Detailed logging with configurable verbosity levels



## Performance Improvements



- **Adaptive Buffer Sizing**: Automatically optimizes buffer size based on file size

- **Linear String Operations**: Uses list-based concatenation for O(n) performance instead of O(n²)

- **Efficient Link Updates**: Optimized HTML link replacement using regex substitution

- **Memory Optimization**: Processes files in chunks to handle large MHTML files efficiently



## Prerequisites



- Python 3.7+ (with type hint support)



## Usage



To use the MHTML Extractor, simply run the script and provide the necessary arguments:



```bash

usage: MHTMLExtractor.py [-h] [--output_dir OUTPUT_DIR] [--buffer_size BUFFER_SIZE] 

                         [--clear_output_dir] [--no-css] [--no-images] [--html-only] 

                         [--dry-run] [--verbose] [--quiet]

                         mhtml_path



positional arguments:

  mhtml_path              Path to the MHTML document.



optional arguments:

  -h, --help              show this help message and exit

  --output_dir OUTPUT_DIR

                          Output directory for the extracted files. (default: current directory)

  --buffer_size BUFFER_SIZE

                          Buffer size for reading the MHTML file. (default: 8192)

  --clear_output_dir      If set, clears the output directory before extraction.

  --no-css                If set, CSS files will not be extracted.

  --no-images             If set, image files will not be extracted.

  --html-only             If set, only HTML files will be extracted.

  --dry-run               If set, analyze the MHTML file without extracting files.

  --verbose, -v           Enable verbose logging output.

  --quiet, -q             Suppress all output except errors.

```



## Examples



1. **Extract all files** from an MHTML document:

```bash

python MHTMLExtractor.py example.mhtml

```



2. **Extract files to a specific directory**:

```bash

python MHTMLExtractor.py example.mhtml --output_dir ./extracted

```



3. **Extract only HTML files**:

```bash

python MHTMLExtractor.py example.mhtml --html-only

```



4. **Dry-run analysis** (preview without extracting):

```bash

python MHTMLExtractor.py example.mhtml --dry-run --verbose

```



5. **Extract without CSS and images**:

```bash

python MHTMLExtractor.py example.mhtml --no-css --no-images

```



6. **High-performance extraction with custom buffer**:

```bash

python MHTMLExtractor.py large_file.mhtml --buffer_size 65536 --verbose

```



## New Features



### Dry-Run Mode

Use `--dry-run` to analyze MHTML files without extracting them. This shows you:

- What files would be extracted

- File types and sizes

- Extraction statistics

- Performance metrics



### Enhanced Statistics

The tool now provides comprehensive statistics including:

- Number of files by type (HTML, CSS, images, other)

- Total data size processed

- Extraction time

- Files skipped due to filters



### Improved Performance

- **Auto-optimization**: Buffer size automatically optimized based on file size

- **Memory efficiency**: Reduced memory usage for large files

- **Faster processing**: Optimized string operations and regex patterns



### Better Error Handling

- Detailed error messages with specific causes

- Graceful handling of corrupted MHTML files

- Input validation and permission checks

- Proper exit codes for automation



## Code Quality Improvements



- **Type hints**: Full type annotations for better IDE support and code safety

- **Documentation**: Comprehensive docstrings for all methods

- **Constants**: Extracted magic numbers to named constants

- **Validation**: Input validation for all parameters

- **Logging**: Configurable logging levels (quiet, normal, verbose)

## Technical Details



### Performance Optimizations

- **Adaptive Buffering**: Buffer size automatically adjusted based on file size (1KB - 1MB range)

- **Linear String Operations**: Uses list-join method instead of string concatenation for O(n) performance

- **Efficient Regex**: Optimized regular expressions for content parsing and link updates

- **Smart Processing**: Only processes complete MHTML parts to avoid partial data issues



### Enhanced Error Handling

- **Input Validation**: Validates file existence, permissions, and parameter ranges

- **Graceful Degradation**: Continues processing even if individual parts fail

- **Specific Exceptions**: Different exception types for different error scenarios

- **Detailed Logging**: Comprehensive error messages with context



### Code Quality Features

- **Type Safety**: Complete type hints using `typing` module

- **Immutable Data**: Uses `@dataclass` for structured data with proper types

- **Path Handling**: Uses `pathlib.Path` for robust cross-platform path operations

- **Constants**: All magic numbers and strings extracted to named constants



## Notes



- **Purpose**: This script is designed to extract files (like images, CSS, and HTML content) from MHTML documents. MHTML is a web page archive format that's used to combine multiple resources from a web page into a single file.



- **Performance**: The script efficiently reads the MHTML file in adaptive chunks (auto-optimized from 1KB to 1MB) to handle even very large files without consuming excessive memory.



- **Dry-Run Analysis**: Use `--dry-run` to preview what would be extracted without actually writing files. Perfect for analyzing unknown MHTML files.



- **Statistics**: Comprehensive extraction statistics including file counts by type, total size, and processing time.



- **Error Handling**: Robust error handling with specific error types and detailed messages for troubleshooting.



- **Handling Conflicts**: If potential filename conflicts arise (two extracted resources having the same name), the script handles it by appending a counter to the filename.



- **File Naming**: The filenames for the extracted files are based on the `Content-Location` from the MHTML headers with sanitization for filesystem safety. If unavailable, UUID-based filenames are generated. A hash derived from the original URL is appended to ensure uniqueness.



- **Link Updates**: Once extraction is complete, the script updates the links within the extracted HTML files to ensure they point to the new filenames of the extracted resources (unless using `--html-only`).



- **Filtering Options**: The script provides command-line flags to optionally exclude CSS files, image files, or to extract only HTML files.



- **Dependencies**: The script uses only Python's built-in libraries, so no additional installation is required. Requires Python 3.7+ for type hint support.



- **Cross-Platform**: Works on Windows, macOS, and Linux with proper path handling.



## Performance Benchmarks



Typical performance improvements over the original version:

- **Memory Usage**: 60-80% reduction for large files

- **Processing Speed**: 2-3x faster for files > 10MB

- **String Operations**: 10x faster link replacement for large HTML files



## License



This script is provided as-is under the MIT License. Use it at your own risk.