Struct DirectoryStore 

pub struct DirectoryStore { /* private fields */ }

A data store that persists items to files in a directory.

Files are created with incrementing numerical prefixes and contain batched JSON data. When a file reaches the configured size limit, a new file is created. Completed files are marked with a .temp extension to indicate they are ready for processing.

Each file contains a JSON object with:

• A batch array containing the stored items
• A sentAt timestamp in RFC3339 format
• The store’s writeKey

Implementations

impl DirectoryStore

pub fn new(config: DirectoryConfig) -> Result<Self>

Creates a new DirectoryStore with the specified configuration.

Creates the storage directory if it doesn’t exist. The store will initialize its file index by scanning existing files in the directory.

Arguments

• config - Configuration options for the store

Errors

Returns an IO error if:

• The storage directory cannot be created
• The directory cannot be read when scanning for existing files

Panics

• If max_file_size is less than 100 bytes

pub fn set_file_validator<F>(&mut self, validator: F)

where F: Fn(&Path) -> Result<()> + 'static + Send + Sync,

Sets a validator function that will be called before finalizing each data file.

The validator is called just before a file is marked as complete (renamed with .temp extension). If the validator returns an error, the file will not be finalized and the error will be propagated.

Arguments

• validator - Function that takes a file path and returns Ok(()) if the file is valid

Examples

use std::path::PathBuf;
use std::fs;
use std::io;
use transientdb::{DirectoryConfig, DirectoryStore};

let mut store = DirectoryStore::new(DirectoryConfig {
    write_key: "test".into(),
    storage_location: PathBuf::from("/tmp/data"),
    base_filename: "events".into(),
    max_file_size: 1024,
})?;

// Add a validator that checks file size and JSON validity
store.set_file_validator(|path| {
    // Verify minimum file size
    let metadata = fs::metadata(path)?;
    if metadata.len() < 10 {
        return Err(io::Error::new(io::ErrorKind::Other, "File too small"));
    }

    // Verify file contains valid JSON
    let content = fs::read_to_string(path)?;
    serde_json::from_str::<serde_json::Value>(&content)?;

    Ok(())
});

Trait Implementations

impl DataStore for DirectoryStore

type Output = Vec<PathBuf>

The type of data returned by fetch operations.

fn has_data(&self) -> bool

Checks if the store contains any data that can be fetched.

fn reset(&mut self)

Removes all data from the store and resets it to initial state.

fn append(&mut self, data: Value) -> Result<()>

Appends a new item to the store.

fn fetch( &mut self, count: Option<usize>, max_bytes: Option<usize>, ) -> Result<Option<DataResult<Self::Output>>>

Fetches a batch of data from the store, respecting optional count and size limits.

fn remove(&mut self, data: &[Box<dyn Equivalent>]) -> Result<()>

Removes previously fetched data from the store.