refactor: remove InputReaderAdapter

delorean_parquet/src/lib.rs

@@ -2,55 +2,13 @@
 #![deny(rust_2018_idioms)]
 #![warn(missing_debug_implementations, clippy::explicit_iter_loop)]
 
+// Export the parts of
 pub use parquet::{
     errors::ParquetError,
     file::reader::{Length, TryClone},
 };
-use std::io::{Read, Seek, SeekFrom};
 
 pub mod error;
 pub mod metadata;
 pub mod stats;
 pub mod writer;
-
-/// Adapts an object that implements Read+Seek to something that also
-/// implements the parquet TryClone interface, required by the parquet
-/// reader. This is provided so users of this crate do not have to
-/// implement a parquet specific trait
-struct InputReaderAdapter<R>
-where
-    R: Read + Seek,
-{
-    real_reader: R,
-    size: u64,
-}
-
-impl<R: Read + Seek> InputReaderAdapter<R> {
-    fn new(real_reader: R, size: u64) -> InputReaderAdapter<R> {
-        InputReaderAdapter { real_reader, size }
-    }
-}
-
-impl<R: Read + Seek> Read for InputReaderAdapter<R> {
-    fn read(&mut self, buf: &mut [u8]) -> Result<usize, std::io::Error> {
-        self.real_reader.read(buf)
-    }
-}
-
-impl<R: Read + Seek> Seek for InputReaderAdapter<R> {
-    fn seek(&mut self, pos: SeekFrom) -> Result<u64, std::io::Error> {
-        self.real_reader.seek(pos)
-    }
-}
-
-impl<R: Read + Seek> TryClone for InputReaderAdapter<R> {
-    fn try_clone(&self) -> std::result::Result<Self, ParquetError> {
-        Err(ParquetError::NYI(String::from("TryClone for input reader")))
-    }
-}
-
-impl<R: Read + Seek> Length for InputReaderAdapter<R> {
-    fn len(&self) -> u64 {
-        self.size
-    }
-}

delorean_parquet/src/metadata.rs

@@ -10,7 +10,7 @@ use delorean_table_schema::DataType;
 
 use crate::{
     error::{Error, Result},
-    InputReaderAdapter,
+    Length, TryClone,
 };
 
 pub fn parquet_schema_as_string(parquet_schema: &schema::types::Type) -> String {
@@ -36,23 +36,22 @@ pub fn data_type_from_parquet_type(parquet_type: parquet::basic::Type) -> DataTy
 
 /// Print parquet metadata that can be read from `input`, with a total
 /// size of `input_size` byes
-pub fn print_parquet_metadata<R: 'static>(input: R, input_size: u64) -> Result<()>
+pub fn print_parquet_metadata<R: 'static>(input: R) -> Result<()>
 where
-    R: Read + Seek,
+    R: Read + Seek + TryClone + Length,
 {
-    let input_adapter = InputReaderAdapter::new(input, input_size);
+    let input_len = input.len();
 
-    let reader =
-        SerializedFileReader::new(input_adapter).map_err(|e| Error::ParquetLibraryError {
-            message: String::from("Creating parquet reader"),
-            source: e,
-        })?;
+    let reader = SerializedFileReader::new(input).map_err(|e| Error::ParquetLibraryError {
+        message: String::from("Creating parquet reader"),
+        source: e,
+    })?;
 
     let parquet_metadata = reader.metadata();
     let file_metadata = parquet_metadata.file_metadata();
     let num_columns = file_metadata.schema_descr().num_columns();
 
-    println!("Parquet file size: {} bytes", input_size);
+    println!("Parquet file size: {} bytes", input_len);
     println!(
         "Parquet file Schema: {}",
         parquet_schema_as_string(file_metadata.schema()).trim_end()

delorean_parquet/src/stats.rs

@@ -12,24 +12,21 @@ use delorean_table::stats::{ColumnStats, ColumnStatsBuilder};
 use crate::{
     error::{Error, Result},
     metadata::data_type_from_parquet_type,
-    InputReaderAdapter,
+    Length, TryClone,
 };
 
 /// Calculate storage statistics for a particular parquet file that can
 /// be read from `input`, with a total size of `input_size` byes
 ///
 /// Returns a Vec of ColumnStats, one for each column in the input
-pub fn col_stats<R: 'static>(input: R, input_size: u64) -> Result<Vec<ColumnStats>>
+pub fn col_stats<R: 'static>(input: R) -> Result<Vec<ColumnStats>>
 where
-    R: Read + Seek,
+    R: Read + Seek + TryClone + Length,
 {
-    let input_adapter = InputReaderAdapter::new(input, input_size);
-
-    let reader =
-        SerializedFileReader::new(input_adapter).map_err(|e| Error::ParquetLibraryError {
-            message: String::from("Creating parquet reader"),
-            source: e,
-        })?;
+    let reader = SerializedFileReader::new(input).map_err(|e| Error::ParquetLibraryError {
+        message: String::from("Creating parquet reader"),
+        source: e,
+    })?;
 
     let mut stats_builders = BTreeMap::new();
 

src/commands/file_meta.rs

@@ -40,8 +40,7 @@ pub fn dump_meta(input_filename: &str) -> Result<()> {
             Ok(())
         }
         FileType::Parquet => {
-            let input_len = input_reader.len();
-            print_parquet_metadata(input_reader, input_len)
+            print_parquet_metadata(input_reader)
                 .map_err(|e| Error::UnableDumpToParquetMetadata { source: e })?;
             Ok(())
         }

src/commands/input.rs

@@ -6,6 +6,7 @@ use std::io::{BufRead, BufReader, Cursor, Read, Seek, SeekFrom};
 use std::path::Path;
 
 use crate::commands::error::{Error, Result};
+use delorean_parquet::ParquetError;
 
 #[derive(Debug)]
 pub enum FileType {
@@ -82,17 +83,21 @@ impl Seek for InputReader {
     }
 }
 
-impl Read for InputReader {
-    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+impl delorean_parquet::Length for InputReader {
+    fn len(&self) -> u64 {
         match self {
-            InputReader::FileInputType(file_input_reader) => file_input_reader.reader.read(buf),
-            InputReader::MemoryInputType(memory_input_reader) => {
-                memory_input_reader.cursor.read(buf)
-            }
+            InputReader::FileInputType(file_input_reader) => file_input_reader.file_size,
+            InputReader::MemoryInputType(memory_input_reader) => memory_input_reader.file_size,
         }
     }
 }
 
+impl delorean_parquet::TryClone for InputReader {
+    fn try_clone(&self) -> std::result::Result<Self, ParquetError> {
+        Err(ParquetError::NYI(String::from("TryClone for input reader")))
+    }
+}
+
 impl BufRead for InputReader {
     fn fill_buf(&mut self) -> io::Result<&[u8]> {
         match self {
@@ -112,6 +117,17 @@ impl BufRead for InputReader {
     }
 }
 
+impl Read for InputReader {
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize, std::io::Error> {
+        match self {
+            InputReader::FileInputType(file_input_reader) => file_input_reader.reader.read(buf),
+            InputReader::MemoryInputType(memory_input_reader) => {
+                memory_input_reader.cursor.read(buf)
+            }
+        }
+    }
+}
+
 impl InputReader {
     pub fn file_type(&self) -> &FileType {
         match self {

src/commands/stats.rs

@@ -30,7 +30,7 @@ pub fn stats(input_filename: &str) -> Result<()> {
             let input_len = input_reader.len();
             (
                 input_len,
-                col_stats(input_reader, input_len)
+                col_stats(input_reader)
                     .map_err(|e| Error::UnableDumpToParquetMetadata { source: e })?,
             )
         }