Struct LowLevelJsonReader

pub struct LowLevelJsonReader { /* private fields */ }

A low-level JSON parser acting on a provided buffer.

Does not allocate except a stack to check if array and object opening and closing are properly nested. This stack size might be limited using the method with_max_stack_size.

use json_event_parser::{LowLevelJsonReader, JsonEvent, LowLevelJsonReaderResult};

let mut reader = LowLevelJsonReader::new();
assert!(matches!(
    reader.read_next_event(b"{\"foo".as_slice(), false),
    LowLevelJsonReaderResult { consumed_bytes: 1, event: Some(Ok(JsonEvent::StartObject))}
));
assert!(matches!(
    reader.read_next_event(b"\"foo".as_slice(), false),
    LowLevelJsonReaderResult { consumed_bytes: 0, event: None }
));
assert!(matches!(
    reader.read_next_event(b"\"foo\": 1}".as_slice(), false),
    LowLevelJsonReaderResult { consumed_bytes: 5, event: Some(Ok(JsonEvent::ObjectKey(Cow::Borrowed("foo")))) }
));
assert!(matches!(
    reader.read_next_event(b": 1}".as_slice(), false),
    LowLevelJsonReaderResult { consumed_bytes: 3, event: Some(Ok(JsonEvent::Number(Cow::Borrowed("1")))) }
));
assert!(matches!(
    reader.read_next_event(b"}".as_slice(), false),
    LowLevelJsonReaderResult { consumed_bytes: 1, event: Some(Ok(JsonEvent::EndObject)) }
));
assert!(matches!(
    reader.read_next_event(b"".as_slice(), true),
    LowLevelJsonReaderResult { consumed_bytes: 0, event: Some(Ok(JsonEvent::Eof)) }
));

Implementations

impl LowLevelJsonReader

pub const fn new() -> Self

pub fn with_max_stack_size(self, size: usize) -> Self

Maximal allowed number of nested object and array openings. Infinite by default.

pub fn read_next_event<'a>( &mut self, input_buffer: &'a [u8], is_ending: bool, ) -> LowLevelJsonReaderResult<'a>

Reads a new event from the data in input_buffer.

is_ending must be set to true if all the JSON data have been already consumed or are in input_buffer.