This commit is contained in:
parent
5ae8b48845
commit
63f4dce705
46
Cargo.lock
generated
46
Cargo.lock
generated
@ -11,6 +11,24 @@ dependencies = [
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"memchr",
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]
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[[package]]
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name = "bincode"
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version = "2.0.0-rc.1"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "f609ceb2c41b0d0277314a789ef0e7eb14593d5485f7c67320bed3924ebb1b33"
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dependencies = [
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"bincode_derive",
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]
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[[package]]
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name = "bincode_derive"
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version = "2.0.0-rc.1"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "913287a8f3e00db4c7ae1b87e9b9b8cebd6b89217eaadfc281fa5c897da35dc3"
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dependencies = [
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"virtue",
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]
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[[package]]
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name = "const_format"
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version = "0.2.22"
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@ -78,10 +96,32 @@ version = "0.6.25"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
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[[package]]
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name = "serde"
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version = "1.0.136"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789"
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dependencies = [
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"serde_derive",
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]
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[[package]]
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name = "serde_derive"
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version = "1.0.136"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "08597e7152fcd306f41838ed3e37be9eaeed2b61c42e2117266a554fab4662f9"
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dependencies = [
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"proc-macro2",
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"quote",
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"syn",
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]
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[[package]]
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name = "sqlite_clone"
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version = "0.1.0"
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dependencies = [
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"bincode",
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"serde",
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"sscanf",
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]
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@ -125,3 +165,9 @@ name = "unicode-xid"
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version = "0.2.2"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
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[[package]]
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name = "virtue"
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version = "0.0.7"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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checksum = "757cfbfe0d17ee6f22fe97e536d463047d451b47cf9d11e2b7d1398b0ef274dd"
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@ -7,3 +7,5 @@ edition = "2021"
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[dependencies]
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sscanf = {version="0.2.1"}
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bincode = "2.0.0-rc.1"
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serde = {version="1.0.136", features=["derive"]}
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31
src/main.rs
31
src/main.rs
@ -1,18 +1,25 @@
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mod page;
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mod pager;
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mod row;
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mod statement;
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mod table;
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use crate::statement::ExecuteResult;
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use crate::table::Table;
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use std::io;
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use std::io::Write;
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use std::process::exit;
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struct InputBuffer {
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buffer: Option<String>,
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table: Table,
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}
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impl InputBuffer {
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pub fn new() -> Self {
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return Self {
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buffer: None
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buffer: None,
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table: Table::new(),
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};
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}
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@ -34,11 +41,11 @@ impl InputBuffer {
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Err(String::from("could not handle input"))
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}
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}
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_ => { Err(String::from("Could not initialize buffer")) }
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_ => Err(String::from("Could not initialize buffer")),
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}
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}
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pub(crate) fn parse(&self) {
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pub(crate) fn parse(&mut self) {
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match &self.buffer {
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Some(command) => {
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if command.starts_with(".") {
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@ -46,7 +53,15 @@ impl InputBuffer {
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} else {
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match Self::prepare_statement(&command.replace("\n", "")) {
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Ok(statement) => {
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statement.execute()
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let execution_result = statement.execute(&mut self.table);
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match execution_result {
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ExecuteResult::Success => {
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println!("success")
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}
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_ => {
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println!("failure")
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}
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}
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}
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Err(e) => {
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println!("{}", e);
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@ -74,14 +89,10 @@ impl InputBuffer {
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}
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}
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fn main() -> Result<(), String> {
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let mut input_buffer = InputBuffer::new();
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loop {
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input_buffer
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.print_prompt()
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.read_input()?
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.parse()
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input_buffer.print_prompt().read_input()?.parse()
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}
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}
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28
src/page.rs
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28
src/page.rs
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@ -0,0 +1,28 @@
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use std::ops::{Deref, DerefMut};
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#[derive(Debug, Clone)]
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pub struct Page {
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buffer: Vec<u8>,
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}
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impl Page {
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pub fn new(buffer: Vec<u8>) -> Self {
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Self {
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buffer,
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}
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}
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}
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impl Deref for Page {
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type Target = Vec<u8>;
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fn deref(&self) -> &Self::Target {
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&self.buffer
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}
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}
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impl DerefMut for Page {
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fn deref_mut(&mut self) -> &mut Self::Target {
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&mut self.buffer
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}
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}
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35
src/pager.rs
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35
src/pager.rs
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@ -0,0 +1,35 @@
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use crate::page::Page;
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pub struct Pager {
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pages: Vec<Option<Page>>,
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page_size: usize,
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}
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impl Pager {
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pub fn new(page_size: usize) -> Self {
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Self {
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page_size,
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pages: Vec::new(),
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}
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}
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pub fn get_mut_or_alloc(&mut self, page_num: usize) -> &mut Page {
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if page_num >= self.pages.len() {
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self.grow_pages(page_num)
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}
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if self.pages[page_num].is_none() {
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let buf = vec![0; self.page_size];
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let page = Page::new(buf);
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self.pages[page_num] = Some(page)
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}
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self.pages[page_num].as_mut().unwrap()
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}
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#[inline]
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fn grow_pages(&mut self, index: usize) {
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println!("debug: Growing pages");
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self.pages.resize(index + 1, None)
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}
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}
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84
src/row.rs
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84
src/row.rs
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@ -0,0 +1,84 @@
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use std::{iter, slice};
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use std::io::Write;
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use bincode::{Decode, Encode};
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use bincode::config::Configuration;
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use bincode::error::{DecodeError, EncodeError};
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const COLUMN_USERNAME_SIZE: usize = 32;
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const COLUMN_EMAIL_SIZE: usize = 255;
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#[derive(Encode, Decode)]
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pub struct Row {
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pub id: u32,
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pub username: [u8; COLUMN_USERNAME_SIZE],
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pub email: [u8; COLUMN_EMAIL_SIZE],
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}
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pub trait Serialize {
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fn serialize(&self) -> Result<Vec<u8>, EncodeError>;
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fn deserialize(buffer: &[u8]) -> Result<Self, DecodeError>
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where
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Self: Sized;
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}
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impl Serialize for Row {
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fn serialize(&self) -> Result<Vec<u8>, EncodeError> {
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bincode::encode_to_vec(self, bincode::config::standard())
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}
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fn deserialize(buffer: &[u8]) -> Result<Self, DecodeError> {
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match bincode::decode_from_slice::<Self, Configuration>(buffer, bincode::config::standard())
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{
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Ok((row, _)) => Ok(row),
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Err(e) => Err(e),
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}
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}
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}
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impl Row {
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pub fn new(id: u32, username: String, email: String) -> Result<Self, String> {
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let username_bytes = username.as_bytes();
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let email_bytes = email.as_bytes();
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if username_bytes.len() > COLUMN_USERNAME_SIZE {
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Err(String::from("username is too long"))
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} else if email_bytes.len() > COLUMN_EMAIL_SIZE {
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Err(String::from("email is too long"))
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} else {
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let username_buffer = &mut [0; COLUMN_USERNAME_SIZE];
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if let Err(_) = pad_buffer(username_buffer, username_bytes) {
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panic!("could not pad username buffer")
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}
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let email_buffer = &mut [0; COLUMN_EMAIL_SIZE];
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if let Err(_) = pad_buffer(email_buffer, username_bytes) {
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panic!("could not pad username buffer")
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}
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Ok(Self {
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id,
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username: *username_buffer,
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email: *email_buffer,
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})
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}
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}
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pub(crate) fn print(&self) {
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println!("({}, {}, {})", self.id, String::from_utf8(self.email.to_vec()).unwrap(), String::from_utf8(self.username.to_vec()).unwrap())
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}
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}
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fn pad_buffer(mut bytes: &mut [u8], source: &[u8]) -> std::io::Result<usize> {
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bytes.write(source)
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}
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pub struct RowIter<'a> {
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inner: slice::Iter<'a, Row>,
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}
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impl<'a> iter::Iterator for RowIter<'a> {
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type Item = &'a Row;
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fn next(&mut self) -> Option<Self::Item> {
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self.inner.next()
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}
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}
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@ -1,50 +1,16 @@
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use std::io::Write;
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use std::mem::size_of;
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use crate::row::Serialize;
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use crate::table::Table;
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use crate::{row};
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pub enum StatementType {
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Insert {
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row: Row
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},
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Insert { row: row::Row },
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Select,
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}
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const COLUMN_USERNAME_SIZE: usize = 32;
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const COLUMN_EMAIL_SIZE: usize = 255;
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pub struct Row {
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id: u32,
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username: [u8; COLUMN_USERNAME_SIZE],
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email: [u8; COLUMN_EMAIL_SIZE],
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}
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impl Row {
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fn new(id: u32, username: String, email: String) -> Result<Self, String> {
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let username_bytes = username.as_bytes();
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let email_bytes = email.as_bytes();
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if username_bytes.len() > COLUMN_USERNAME_SIZE {
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Err(String::from("username is too long"))
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} else if email_bytes.len() > COLUMN_EMAIL_SIZE {
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Err(String::from("email is too long"))
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} else {
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let username_buffer = &mut [0; COLUMN_USERNAME_SIZE];
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if let Err(_) = pad_buffer(username_buffer, username_bytes) {
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panic!("could not pad username buffer")
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}
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let email_buffer = &mut [0; COLUMN_EMAIL_SIZE];
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if let Err(_) = pad_buffer(email_buffer, username_bytes) {
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panic!("could not pad username buffer")
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}
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Ok(Self {
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id,
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username: *username_buffer,
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email: *email_buffer,
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})
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}
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}
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}
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fn pad_buffer(mut bytes: &mut [u8], source: &[u8]) -> std::io::Result<usize> {
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bytes.write(source)
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pub enum ExecuteResult {
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Error { error: String },
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Success,
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}
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pub struct Statement {
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@ -53,43 +19,50 @@ pub struct Statement {
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impl Statement {
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pub fn new(statement_type: StatementType) -> Self {
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Self {
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statement_type,
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}
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Self { statement_type }
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}
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pub fn parse_statement(command: &String) -> Result<Self, String> {
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if command.starts_with("insert") {
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match sscanf::scanf!(command, "insert {} {} {}", usize, str, str) {
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Ok((id, username, email)) => {
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match Row::new(u32::try_from(id).unwrap(), username.to_string(), email.to_string()) {
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Ok(row) => {
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Ok(Statement::new(StatementType::Insert { row: row }))
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}
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Err(e) => { Err(e) }
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match row::Row::new(
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u32::try_from(id).unwrap(),
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username.to_string(),
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email.to_string(),
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) {
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Ok(row) => Ok(Statement::new(StatementType::Insert { row })),
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Err(e) => Err(e),
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}
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}
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_ => {
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Err(String::from("could not parse insert statement"))
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}
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_ => Err(String::from("could not parse insert statement")),
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}
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} else if command.starts_with("select") {
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Ok(Statement::new(StatementType::Select))
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} else {
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return Err(String::from("Could not parse command"));
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Err(String::from("Could not parse command"))
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}
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}
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pub(crate) fn execute(&self) {
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pub(crate) fn execute(&self, table: &mut Table) -> ExecuteResult {
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match &self.statement_type {
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StatementType::Insert { row } => {
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println!("This is where you do an insert {}", row.id)
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StatementType::Insert { row } => match row.serialize() {
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Err(e) => ExecuteResult::Error {
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error: e.to_string(),
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},
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Ok(serialization) => {
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table.append_row(serialization);
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ExecuteResult::Success
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}
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},
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StatementType::Select => {
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println!("This is where you do an select")
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let rows = table.get_rows();
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for row in rows {
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row.print()
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}
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return ExecuteResult::Success;
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}
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}
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}
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}
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|
61
src/table.rs
Normal file
61
src/table.rs
Normal file
@ -0,0 +1,61 @@
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use crate::pager::Pager;
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use crate::row;
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use std::mem::size_of;
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use std::ops::DerefMut;
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use crate::row::Row;
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use crate::row::Serialize;
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const PAGE_SIZE: usize = 4096;
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|
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pub struct Table {
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num_rows: usize,
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pager: Pager,
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}
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|
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impl Table {
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pub fn new() -> Self {
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Self {
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num_rows: 0,
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pager: Pager::new(PAGE_SIZE),
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}
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}
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pub(crate) fn append_row(&mut self, row: Vec<u8>) {
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let row_size = size_of::<row::Row>();
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let page_num = self.num_rows / self.rows_per_page(row_size);
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let row_offset = self.num_rows % self.rows_per_page(row_size);
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let page = self.pager.get_mut_or_alloc(page_num);
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let byte_offset = row_offset * row_size;
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page.deref_mut()
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.splice(byte_offset..byte_offset + row_size, row);
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self.num_rows += 1;
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}
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pub fn row(&mut self, row_num: usize) -> Row {
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let row_size = size_of::<row::Row>();
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let page_num = row_num / self.rows_per_page(row_size);
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let row_offset = row_num % self.rows_per_page(row_size);
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let byte_offset = row_offset * row_size;
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let page = self.pager.get_mut_or_alloc(page_num);
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Row::deserialize(&page[byte_offset..byte_offset + row_size]).unwrap()
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}
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|
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#[inline]
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fn rows_per_page(&self, row_size: usize) -> usize {
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PAGE_SIZE / row_size
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}
|
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|
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pub(crate) fn get_rows(&mut self) -> Vec<Row> {
|
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let mut rows: Vec<Row> = Vec::with_capacity(self.num_rows);
|
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for i in 0..self.num_rows {
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rows.push(self.row(i))
|
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}
|
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|
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rows
|
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}
|
||||
}
|
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