# NdjsonZst
NdjsonZst is a Rust library for writing and reading newline-delimited JSON (NDJSON) files that are compressed using Zstandard (zstd). This library provides two primary structures: `NdjsonZstWriter` and `NdjsonZstReader`, enabling you to efficiently handle NDJSON files with compression.
## Features
- **Write NDJSON with Zstandard Compression**: Use `NdjsonZstWriter` to write NDJSON data to a compressed file.
- **Read NDJSON from Compressed Files**: Use `NdjsonZstReader` to read NDJSON data from a compressed file.
- **Optional Line Removal**: `NdjsonZstWriter` allows writing data while removing newline (`\n`) and carriage return (`\r`) characters from the input string.
## Usage
### Adding Dependencies
To use NdjsonZst, add the following dependencies to your `Cargo.toml`:
```toml
[dependencies]
ndjson_zst = "0.1.0"
```
### Example
#### Writing NDJSON Data
```rust
use std::fs::File;
use ndjson_zst::NdjsonZstWriter;
fn main() {
let file_path = "data.zst";
let mut writer = NdjsonZstWriter::from(file_path);
writer.write(r#"{"name": "Alice", "age": 30}"#);
writer.write_with_remove_line("Line with\nnewlines\n");
}
```
#### Reading NDJSON Data
```rust
use ndjson_zst::NdjsonZstReader;
fn main() {
let file_path = "data.zst";
let reader = NdjsonZstReader::from(file_path);
for line in reader.lines() {
println!("{}", line);
}
}
```
### API Documentation
#### `NdjsonZstWriter`
##### `from(value: &str) -> Self`
Creates a new `NdjsonZstWriter` instance from a file path.
##### `new(f: File) -> Self`
Creates a new `NdjsonZstWriter` instance from a `File`.
##### `write(&mut self, data: &str)`
Writes a string to the NDJSON file, followed by a newline character.
##### `write_with_remove_line(&mut self, data: &str)`
Writes a string to the NDJSON file after removing all newline (`\n`) and carriage return (`\r`) characters, followed by a newline character.
#### `NdjsonZstReader`
##### `from(value: &str) -> Self`
Creates a new `NdjsonZstReader` instance from a file path.
##### `new(f: File) -> Self`
Creates a new `NdjsonZstReader` instance from a `File`.
##### `lines(&self) -> std::str::Lines`
Returns an iterator over the lines of the NDJSON file.
## License
This project is licensed under the MIT License.
## Contributing
Contributions are welcome! Please feel free to submit a pull request or open an issue if you have any suggestions or improvements.
## Acknowledgements
- [zstd-rs](https://github.com/gyscos/zstd-rs) for the Zstandard bindings for Rust.
## Notes
- The current implementation of `NdjsonZstReader` reads the entire file into memory. Future improvements may include supporting streaming reads for handling large files efficiently.
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This README provides a basic overview and example usage of the NdjsonZst library. For more detailed information, please refer to the source code and inline documentation.