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use std::path::{Path, PathBuf};
use polars_core::cloud::CloudOptions;
use polars_core::prelude::*;
#[cfg(feature = "async")]
use polars_io::async_glob;
use polars_io::parquet::ParallelStrategy;
use polars_io::{is_cloud_url, RowCount};
use crate::prelude::*;
#[derive(Clone)]
pub struct ScanArgsParquet {
pub n_rows: Option<usize>,
pub cache: bool,
pub parallel: ParallelStrategy,
pub rechunk: bool,
pub row_count: Option<RowCount>,
pub low_memory: bool,
pub cloud_options: Option<CloudOptions>,
}
impl Default for ScanArgsParquet {
fn default() -> Self {
Self {
n_rows: None,
cache: true,
parallel: Default::default(),
rechunk: true,
row_count: None,
low_memory: false,
cloud_options: None,
}
}
}
impl LazyFrame {
#[allow(clippy::too_many_arguments)]
fn scan_parquet_impl(
path: impl AsRef<Path>,
n_rows: Option<usize>,
cache: bool,
parallel: ParallelStrategy,
row_count: Option<RowCount>,
rechunk: bool,
low_memory: bool,
cloud_options: Option<CloudOptions>,
) -> PolarsResult<Self> {
let mut lf: LazyFrame = LogicalPlanBuilder::scan_parquet(
path.as_ref(),
n_rows,
cache,
parallel,
None,
rechunk,
low_memory,
cloud_options,
)?
.build()
.into();
if let Some(row_count) = row_count {
lf = lf.with_row_count(&row_count.name, Some(row_count.offset))
}
lf.opt_state.file_caching = true;
Ok(lf)
}
fn concat_impl(lfs: Vec<LazyFrame>, args: ScanArgsParquet) -> PolarsResult<LazyFrame> {
concat_impl(&lfs, args.rechunk, true, true).map(|mut lf| {
if let Some(n_rows) = args.n_rows {
lf = lf.slice(0, n_rows as IdxSize)
};
if let Some(rc) = args.row_count {
lf = lf.with_row_count(&rc.name, Some(rc.offset))
};
lf
})
}
#[deprecated(note = "please use `concat_lf` instead")]
pub fn scan_parquet_files<P: AsRef<Path>>(
paths: Vec<P>,
args: ScanArgsParquet,
) -> PolarsResult<Self> {
let lfs = paths
.iter()
.map(|p| {
Self::scan_parquet_impl(
p,
args.n_rows,
args.cache,
args.parallel,
None,
args.rechunk,
args.low_memory,
args.cloud_options.clone(),
)
})
.collect::<PolarsResult<Vec<_>>>()?;
Self::concat_impl(lfs, args)
}
pub fn scan_parquet(path: impl AsRef<Path>, args: ScanArgsParquet) -> PolarsResult<Self> {
let path = path.as_ref();
let path_str = path.to_string_lossy();
if path_str.contains('*') {
let paths = if is_cloud_url(path) {
#[cfg(feature = "async")]
{
Box::new(
async_glob(&path_str, args.cloud_options.as_ref())?
.into_iter()
.map(|a| Ok(PathBuf::from(&a))),
)
}
#[cfg(not(feature = "async"))]
panic!("Feature `async` must be enabled to use globbing patterns with cloud urls.")
} else {
Box::new(
glob::glob(&path_str).map_err(|_| {
PolarsError::ComputeError("invalid glob pattern given".into())
})?,
) as Box<dyn Iterator<Item = Result<PathBuf, _>>>
};
let lfs = paths
.map(|r| {
let path = r.map_err(|e| PolarsError::ComputeError(format!("{e}").into()))?;
Self::scan_parquet_impl(
path.clone(),
args.n_rows,
args.cache,
ParallelStrategy::None,
None,
false,
args.low_memory,
args.cloud_options.clone(),
)
.map_err(|e| {
PolarsError::ComputeError(
format!("While reading {} got {e:?}.", path.display()).into(),
)
})
})
.collect::<PolarsResult<Vec<_>>>()?;
if lfs.is_empty() {
return PolarsResult::Err(PolarsError::ComputeError(
format!("Could not load any dataframes from {path_str}").into(),
));
}
Self::concat_impl(lfs, args)
} else {
Self::scan_parquet_impl(
path,
args.n_rows,
args.cache,
args.parallel,
args.row_count,
args.rechunk,
args.low_memory,
args.cloud_options,
)
}
}
}