mongodb-schema-parser
Infer a probabilistic schema for a MongoDB collection. This library is meant to be used in Rust or as Web Assembly module in JavaScript.
Usage: in Rust
use SchemaParser
pub fn main () {
let mut file = fs::read_to_string("examples/fanclub.json").unwrap();
let file: Vec<&str> = file.split("\n").collect();
let schema_parser = SchemaParser::new();
for json in file {
schema_parser.write(&json)?;
}
let result = schema_parser.flush();
println!("{:?}", result);
}Rust API:
schema_parser = SchemaParser::new() -> Self
Creates a new SchemaParser instance.
schema_parser.write_bson(doc: Document) -> Result((), failure::Error)
Start populating instantiated schema_parser with Bson OrderedDocument. This should be called for each document you add:
use bson::{doc, bson};
let schema_parser = SchemaParser::new()
schema_parser.write_bson(doc! {"name": "Nori", "type": "Norwegian Forest Cat"});
schema_parser.write_bson(doc! {"name": "Rey", "type": "Viszla"});
schema_parser.write_json(json: &str) -> Result((), failure::Error)
Start populating instantiated schema_parser with a string slice. This should also be called individually for each document:
let schema_parser = SchemaParser::new()
schema_parser.write_json(r#"{"name": "Chashu", "type": "Norwegian Forest Cat"}"#);
schema_parser.write_bson(r#"{"name": "Rey", "type": "Viszla"}"#);
schema_parser.flush() -> SchemaParser
Internally this finalizes the output schema with missing fields, duplicates and probability calculations. SchemaParser is ready to be used after this step.
schema_parser.to_json() -> Result(String, failure::Error)
Returns a serde serialized version of the resulting struct. Before using
.to_json(), a .flush() should be called to finalize schema.
Usage: in JavaScript
Make sure your environment is setup for WebAssembly usage. Check out CONTRIBUTING.md for more detailed instructions.
var schemaWasm = import('@mongodb-rust/wasm-schema-parser')
schemaWasm.then(module => {
var schemaParser = new module.SchemaParser()
try {
schemaParser.writeJson('{"name": "Chashu", "type": "Norwegian Forest Cat"}')
} catch (e) {
throw new Error("schema-parser: Could not write Json", e)
}
var result = schemaParser.toObject()
console.log(result)
})
.catch(e => console.error('Cannot load @mongodb-rust/wasm-schema-parser', e))JavaScript API:
schemaParser = new SchemaParser()
Creates a new SchemaParser instance.
schemaParser.writeRaw(bsonBuf)
Writes a document in raw BSON buffer form to Schema Parser. This buffer can be obtained from MongoDB by passing the raw flag to node driver.
schemaParser.writeJson(json)
Writes a document in a form of json string to SchemaParser.
schema = schemaParser.toJson()
Returns parsed schema in json form.
schema = schemaParser.toObject()
Returns parsed schema as a JavaScript Object. Eliminates the need to call
JSON.parse() on a JSON string.
Installation
$ cargo add mongodb-schema-parser