Struct YourDb 

pub struct YourDb { /* private fields */ }

Small file-backed key/value JSON DB with optional secondary indexes.

• Page 0 is reserved for the index (key -> page_id) serialized as JSON.
• Pages start at 1 for records.
• Each record page layout: [u32 little-endian length][json bytes][padding…]

Improvements vs original:

• safer page length checks (no panics),
• selective secondary indexing (only index fields present in indexed_fields set; empty set = index all),
• helper methods: list_keys, count, compact, etc.

Implementations

impl YourDb

pub fn open(path: &str) -> Result<Self, DbError>

Open existing DB or create a new one if path missing.

Examples found in repository

examples/basic.rs (line 5)

fn main() -> Result<(), DbError> {
    let mut db = YourDb::open("test.db")?;
    db.put("hello", &json!({ "msg": "world" }))?;
    db.flush()?;
    let val = db.get("hello")?;
    println!("{:?}", val);
    Ok(())
}

pub fn put(&mut self, key: &str, value: &Value) -> Result<(), DbError>

Put key -> JSON value (replaces existing if present).

Examples found in repository

examples/basic.rs (line 6)

fn main() -> Result<(), DbError> {
    let mut db = YourDb::open("test.db")?;
    db.put("hello", &json!({ "msg": "world" }))?;
    db.flush()?;
    let val = db.get("hello")?;
    println!("{:?}", val);
    Ok(())
}

pub fn get(&self, key: &str) -> Result<Option<Value>, DbError>

Get full JSON value for a key.

Examples found in repository

examples/basic.rs (line 8)

fn main() -> Result<(), DbError> {
    let mut db = YourDb::open("test.db")?;
    db.put("hello", &json!({ "msg": "world" }))?;
    db.flush()?;
    let val = db.get("hello")?;
    println!("{:?}", val);
    Ok(())
}

pub fn flush(&mut self) -> Result<(), DbError>

Flush: write index to page 0 as length-prefixed JSON.

Examples found in repository

examples/basic.rs (line 7)

fn main() -> Result<(), DbError> {
    let mut db = YourDb::open("test.db")?;
    db.put("hello", &json!({ "msg": "world" }))?;
    db.flush()?;
    let val = db.get("hello")?;
    println!("{:?}", val);
    Ok(())
}

pub fn delete(&mut self, key: &str) -> Result<(), DbError>

Delete a key and remove from secondary indexes.

pub fn get_field( &self, key: &str, field: &str, ) -> Result<Option<Value>, DbError>

Return a specific field from the JSON stored at key.

pub fn filter<F>(&self, predicate: F) -> Result<Vec<(String, Value)>, DbError>

where F: Fn(&Value) -> bool,

Filter all records with a predicate function. Be careful: this iterates records.

pub fn query( &self, field: &str, value: impl Into<Value>, ) -> Result<Vec<String>, DbError>

Query by field = value (via secondary index)

pub fn query_page( &self, field: &str, value: impl Into<Value>, limit: usize, offset: usize, ) -> Result<Vec<String>, DbError>

Query page (limit/offset applied)

pub fn export_query( &self, field: &str, value: impl Into<Value>, path: &str, ) -> Result<(), DbError>

Export query results (key -> value) to a JSON file

pub fn export_to_file(&self, path: &str) -> Result<(), DbError>

Export entire DB to a JSON file.

pub fn show_all(&self) -> Result<(), DbError>

Print all keys->json to stdout (for debugging)

pub fn range_query( &self, field: &str, min: Value, max: Value, ) -> Result<Vec<String>, DbError>

Range query (numeric) for a field between min..=max

pub fn update_field( &mut self, key: &str, field: &str, new_value: Value, ) -> Result<(), DbError>

Update a single field on a record (updates secondary indexes accordingly).

pub fn search_contains( &self, field: &str, substring: &str, ) -> Result<Vec<String>, DbError>

Search text fields for substring (only works for string-valued indexed fields).

pub fn list_keys(&self) -> Vec<String>

Return all keys (lightweight)

pub fn count(&self) -> usize

Count records

pub fn compact(&mut self) -> Result<(), DbError>

Compact DB: rewrite record pages sequentially, rebuild index and secondary indexes. Note: this rewrites pages starting at 1 and will update page ids accordingly.