From 2f0f96ce4625d2ef1273c7bea98a1e9415419fdf Mon Sep 17 00:00:00 2001
From: Igor Tolmachev <me@igorek.dev>
Date: Tue, 16 Jul 2024 21:15:38 +0900
Subject: Add BufReader for CD records parser

---
 src/zip/driver.rs | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

(limited to 'src/zip')

diff --git a/src/zip/driver.rs b/src/zip/driver.rs
index 631c4ed..e7878cf 100644
--- a/src/zip/driver.rs
+++ b/src/zip/driver.rs
@@ -9,7 +9,7 @@ use crate::zip::{
 use chrono::{DateTime, Local, NaiveDate, NaiveDateTime, NaiveTime};
 use std::collections::HashMap as Map;
 use std::fs::File;
-use std::io::{Read, Seek, SeekFrom, Write};
+use std::io::{BufReader, Read, Seek, SeekFrom, Write};
 
 fn dos_to_local(date: u16, time: u16) -> ZipResult<DateTime<Local>> {
     Ok(NaiveDateTime::new(
@@ -111,33 +111,32 @@ impl<Io: Read + Seek> ArchiveRead for Zip<Io> {
         let mut indexes = Map::with_capacity(cd_records as usize);
         let mut files = Vec::with_capacity(cd_records as usize);
         io.seek(SeekFrom::Start(cd_pointer))?;
-        let buf = io.read_vec(cd_size as usize)?;
+        let mut buf_reader = BufReader::with_capacity(cd_size.min(131072) as usize, &mut io);
 
-        let mut p: usize = 0;
         for i in 0..cd_records as usize {
-            if u32::from_le_bytes(buf[p..p + 4].try_into().unwrap()) != 0x02014b50 {
+            let buf = buf_reader.read_arr::<46>()?;
+
+            if u32::from_le_bytes(buf[..4].try_into().unwrap()) != 0x02014b50 {
                 return Err(ZipError::InvalidCDRSignature.into());
             }
-            p += 4;
-            let cdr: Cdr = deserialize(&buf[p..p + 42]).unwrap();
+            let cdr: Cdr = deserialize(&buf[4..46]).unwrap();
             let bit_flag = BitFlag::new(cdr.bit_flag);
-            p += 42;
+
+            let name = buf_reader.read_vec(cdr.name_len as usize)?;
             let name = if bit_flag.is_utf8() {
-                String::from_utf8(buf[p..p + cdr.name_len as usize].to_vec())
-                    .map_err(|_| ZipError::InvalidFileName)?
+                String::from_utf8(name).map_err(|_| ZipError::InvalidFileName)?
             } else {
-                String::from_cp437(&buf[p..p + cdr.name_len as usize])
+                String::from_cp437(name)
             };
-            p += cdr.name_len as usize;
-            let extra_fields: Vec<u8> = buf[p..p + cdr.extra_field_len as usize].into();
-            p += cdr.extra_field_len as usize;
+
+            let extra_fields = buf_reader.read_vec(cdr.extra_field_len as usize)?;
+
+            let comment = buf_reader.read_vec(cdr.comment_len as usize)?;
             let comment = if bit_flag.is_utf8() {
-                String::from_utf8(buf[p..p + cdr.comment_len as usize].to_vec())
-                    .map_err(|_| ZipError::InvalidFileComment)?
+                String::from_utf8(comment).map_err(|_| ZipError::InvalidFileComment)?
             } else {
-                String::from_cp437(&buf[p..p + cdr.comment_len as usize])
+                String::from_cp437(comment)
             };
-            p += cdr.comment_len as usize;
 
             let mut compressed_size = cdr.compressed_size as u64;
             let mut size = cdr.size as u64;
@@ -152,6 +151,7 @@ impl<Io: Read + Seek> ArchiveRead for Zip<Io> {
             while ep < cdr.extra_field_len as usize {
                 let header: ExtraHeader = deserialize(&extra_fields[ep..ep + 4]).unwrap();
                 ep += 4;
+
                 match header.id {
                     // Zip64
                     0x0001 => {
@@ -182,6 +182,7 @@ impl<Io: Read + Seek> ArchiveRead for Zip<Io> {
                             let header: ExtraHeader =
                                 deserialize(&extra_fields[tp..tp + 4]).unwrap();
                             tp += 4;
+
                             match header.id {
                                 0x0001 => {
                                     mtime = ntfs_to_local(u64::from_le_bytes(
-- 
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