document how the benchmark was produced and add python script used

Author: cosmicexplorer

benches/decompress_sink.rs

@@ -3,7 +3,7 @@
 use bencher::{benchmark_group, benchmark_main};
 
 use std::fs;
-use std::io::prelude::*;
+use std::io::{self, prelude::*};
 use std::path::Path;
 
 use bencher::Bencher;
@@ -13,7 +13,14 @@ use zip::read::ZipFile;
 use zip::unstable::read::streaming::StreamingArchive;
 use zip::{result::ZipResult, ZipArchive};
 
-/* This contains the compressed text of King Lear from Project Gutenberg, in the public domain. */
+/* This contains the compressed text of King Lear from Project Gutenberg, in the public domain.
+ * It contains the text of King Lear in multiple formats:
+ * 1. Stored (uncompressed)
+ * 2. Deflated (compresslevel=9)
+ * 3. Bzip2 (compresslevel=9)
+ * It contains 50 of each, with 150 entries total. This is generated by the script
+ * tests/data/generate-king-lear-zip.py.
+ */
 fn get_test_data() -> ZipResult<ZipArchive<fs::File>> {
     let path = Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/data/king-lear-compressed.zip");
     let file = fs::File::open(path)?;
@@ -29,7 +36,7 @@ fn write_entry_to_sink_generic(bench: &mut Bencher) {
         bench.iter(|| {
             for i in 0..archive.len() {
                 let mut f = archive.by_index_generic(i).unwrap();
-                std::io::copy(&mut f, &mut std::io::sink()).unwrap();
+                io::copy(&mut f, &mut io::sink()).unwrap();
             }
         })
     });
@@ -44,7 +51,7 @@ fn write_entry_to_sink_standard(bench: &mut Bencher) {
         bench.iter(|| {
             for i in 0..archive.len() {
                 let mut f = archive.by_index(i).unwrap();
-                std::io::copy(&mut f, &mut std::io::sink()).unwrap();
+                io::copy(&mut f, &mut io::sink()).unwrap();
             }
         })
     });
@@ -63,7 +70,7 @@ fn write_stream_to_sink_generic(bench: &mut Bencher) {
             let mut stream_zip = StreamingArchive::new(&mut reader);
 
             while let Some(mut file) = stream_zip.next_entry().unwrap() {
-                std::io::copy(&mut file, &mut std::io::sink()).unwrap();
+                io::copy(&mut file, &mut io::sink()).unwrap();
             }
             while stream_zip.next_metadata_entry().unwrap().is_some() {}
         })
@@ -77,7 +84,7 @@ fn write_stream_to_sink_standard(bench: &mut Bencher) {
     struct V;
     impl ZipStreamVisitor for V {
         fn visit_file(&mut self, file: &mut ZipFile) -> ZipResult<()> {
-            std::io::copy(file, &mut std::io::sink())?;
+            io::copy(file, &mut io::sink())?;
             Ok(())
         }
         fn visit_additional_metadata(