icbiadb 0.2.3

IcbiaDB | I can't believe it's a database | Simple embedded KV & data structures database
Documentation 
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use super::{BvObj, BvObject, BvString};
use crate::slice;
use crate::normalize_type_name;
use crate::utils::{serialize_object, deserialize, is_int};


// 1. Get mut reference from Db,
// 2. Atomic rewrite data
// 3. ???
// 4. SUCCESS!
#[derive(Debug)]
pub struct BvTuple<'a>{
	inner: &'a mut BvObject,
	elength: Vec<usize>,
	type_map: Vec<BvString>,
}

impl<'a> BvTuple<'a> {
	pub fn from(obj: &'a mut BvObject) -> Self {
		
		let type_map = slice::split(&obj.type_name()[1..obj.type_name().len()-1], b", ").iter()
			.map(|r| BvString::from(normalize_type_name(r).to_vec()))
			.collect::<Vec<_>>();

		let mut elength = vec![];
		for r#type in type_map.iter() {
			let r = match r#type.as_slice() {
				// i8-i128
				[105, 56] => 1,
				[105, 49, 54] => 2,
				[105, 51, 50] => 4,
				[105, 54, 52] => 8,
				[105, 49, 50, 56] => 16,
				// u8-u128
				[117, 56] => 1,
				[117, 49, 54] => 2,
				[117, 51, 50] => 4,
				[117, 54, 52] => 8,
				[117, 49, 50, 56] => 16,
				// f32-f64
				[102, 51, 50] => 4,
				[102, 54, 52] => 8,
				// Str
				[115, 116, 114] => {
					 // Length of str serialized by bincode, usize(str lengt) + str length
					 let curr_pos = elength.iter().sum();
					8 + deserialize::<usize>(&obj[curr_pos..curr_pos+8])
				}
				_ => { panic!("Failed to calculate tuple size") }
			};

			elength.push(r);
		}

		BvTuple {
			inner: obj,
			elength: elength,
			type_map: type_map,
		}
	}

	pub fn get_start(&self, index: usize) -> usize {
		let mut start = 0;
		for i in 0..index {
			start += self.elength[i];
		}

		start
	}

	pub fn get(&'a self, index: usize) -> BvObj<'a> {
		let r = &self.inner[self.get_start(index)..self.get_start(index)+self.elength[index]];

		if self.type_map[index] == "str" {
			BvObj::new(self.type_map[index].as_slice(), r)
		} else if is_int(self.type_map[index].as_slice()) {
			BvObj::new(self.type_map[index].as_slice(), r)
		} else {
			panic!("Failed to implicit cast byte slice to type")
		}
	}

	pub fn value<T: serde::de::DeserializeOwned>(&self, index: usize) -> T {
		let start = self.get_start(index);
		deserialize(&self.inner[start..start+self.elength[index]])
	}

	pub fn set<T: Sized + serde::Serialize>(&mut self, index: usize, value: T) {
		let new_value = serialize_object(&value);
		if self.type_map[index] != new_value.type_name() {
			panic!("Not the same type")
		}

		let length = self.elength[index];
		if length != new_value.len() {
			panic!("Not the same length, are you nuts?! Overwriting len {} with len {}", length, new_value.len())
		}

		let mut x = 0;
		let start = self.get_start(index);
		let new_slice = new_value.as_slice();
		for i in start..start+length {
			self.inner[i] = new_slice[x];
			x += 1;
		}
	}
}