60 lines
2.0 KiB
Rust
60 lines
2.0 KiB
Rust
use anyhow::{bail, Result};
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use sqlite_starter_rust::{
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header::PageHeader, record::parse_record, schema::Schema, varint::parse_varint,
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};
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use std::convert::TryInto;
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use std::fs::File;
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use std::io::prelude::*;
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fn main() -> Result<()> {
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// Parse arguments
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let args = std::env::args().collect::<Vec<_>>();
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match args.len() {
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0 | 1 => bail!("Missing <database path> and <command>"),
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2 => bail!("Missing <command>"),
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_ => {}
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}
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// Read database file into database
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let mut file = File::open(&args[1])?;
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let mut database = Vec::new();
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file.read_to_end(&mut database)?;
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// Parse command and act accordingly
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let command = &args[2];
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match command.as_str() {
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".dbinfo" => {
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// Parse page header from database
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let page_header = PageHeader::parse(&database[100..108])?;
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// Obtain all cell pointers
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let cell_pointers = database[108..]
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.chunks_exact(2)
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.take(page_header.number_of_cells.into())
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.map(|bytes| u16::from_be_bytes(bytes.try_into().unwrap()))
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.collect::<Vec<_>>();
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// Obtain all records from column 5
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#[allow(unused_variables)]
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let schemas = cell_pointers
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.into_iter()
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.map(|cell_pointer| {
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let stream = &database[cell_pointer as usize..];
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let (_, offset) = parse_varint(stream);
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let (_rowid, read_bytes) = parse_varint(&stream[offset..]);
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parse_record(&stream[offset + read_bytes..], 5)
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.map(|record| Schema::parse(record).expect("Invalid record"))
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})
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.collect::<Result<Vec<_>>>()?;
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println!("Your code goes here!");
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// Uncomment this block to pass the first stage
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// println!("number of tables: {}", schemas.len());
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}
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_ => bail!("Missing or invalid command passed: {}", command),
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}
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Ok(())
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}
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