Struct db_dump::Loader

pub struct Loader<'a> { /* private fields */ }

Perform a streaming load of only relevant database tables.

Example

This example loads just the version_downloads.csv table, in which each row is the download count for a single version of a single crate on a single day. We do not store the rows individually in memory but instead stream from the csv to accumulate just a total count per day across all crates, which requires far less memory.

use chrono::NaiveDate;
use std::collections::BTreeMap as Map;

fn main() -> db_dump::Result<()> {
    let mut downloads = Map::<NaiveDate, u64>::new();
    db_dump::Loader::new()
        .version_downloads(|row| {
            *downloads.entry(row.date).or_default() += row.downloads;
        })
        .load("./db-dump.tar.gz")?;

    for (date, count) in downloads {
        println!("{},{}", date, count);
    }

    Ok(())
}

Implementations

impl<'a> Loader<'a>

pub fn new() -> Self

pub fn badges(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn categories(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn crate_owners(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn crates(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn crates_categories(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn crates_keywords(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn dependencies(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn keywords(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn metadata(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn reserved_crate_names(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn teams(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn users(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn version_downloads(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn versions(&mut self, f: impl FnMut(Row) + 'a) -> &mut Self

pub fn load(&mut self, path: impl AsRef<Path>) -> Result<()>

Trait Implementations

impl<'a> Default for Loader<'a>

fn default() -> Loader<'a>

Returns the “default value” for a type.