Improve download speed by using zlib-rs and bigger chunks, and remove bespoke crc32 code

samply-symbols/Cargo.toml

@@ -56,6 +56,7 @@ nom = "7.1.1"
 zerocopy = "0.8"
 zerocopy-derive = "0.8"
 linux-perf-data = "0.11"
+crc32fast = "1.4.2"
 
 [dev-dependencies]
 memmap2 = "0.9.4"

samply-symbols/src/elf.rs

@@ -153,65 +153,12 @@ where
     ))
 }
 
-// https://www-zeuthen.desy.de/unix/unixguide/infohtml/gdb/Separate-Debug-Files.html
-struct GnuDebugLinkCrc32Computer(pub u32);
-
-impl GnuDebugLinkCrc32Computer {
-    pub fn consume(&mut self, buf: &[u8]) {
-        const CRC32_TABLE: [u32; 256] = [
-            0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535,
-            0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd,
-            0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d,
-            0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
-            0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
-            0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
-            0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac,
-            0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
-            0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab,
-            0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
-            0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb,
-            0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
-            0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea,
-            0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce,
-            0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
-            0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
-            0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409,
-            0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
-            0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739,
-            0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
-            0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268,
-            0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0,
-            0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8,
-            0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
-            0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
-            0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703,
-            0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7,
-            0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
-            0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae,
-            0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
-            0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6,
-            0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
-            0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d,
-            0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5,
-            0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
-            0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
-            0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
-        ];
-
-        let mut crc = !self.0;
-        for byte in buf {
-            crc = CRC32_TABLE[(crc as u8 ^ *byte) as usize] ^ (crc >> 8);
-        }
-        self.0 = !crc;
-    }
-}
-
 #[test]
 fn test_crc() {
     fn gnu_debuglink_crc32(initial: u32, buf: &[u8]) -> u32 {
-        let mut computer = GnuDebugLinkCrc32Computer(initial);
-        computer.consume(buf);
-        computer.0
+        let mut hasher = crc32fast::Hasher::new_with_initial(initial);
+        hasher.update(buf);
+        hasher.finalize()
     }
 
     assert_eq!(gnu_debuglink_crc32(0, b"Hello, world!\0"), 2608877062);
@@ -234,7 +181,7 @@ fn test_crc() {
 fn compute_debug_link_crc_of_file_contents<T: FileContents>(
     data: &FileContentsWrapper<T>,
 ) -> Result<u32, Error> {
-    let mut computer = GnuDebugLinkCrc32Computer(0);
+    let mut hasher = crc32fast::Hasher::new();
 
     const CHUNK_SIZE: u64 = 1024 * 1024; // 1MB
     let mut buffer = Vec::with_capacity(CHUNK_SIZE as usize);
@@ -245,11 +192,11 @@ fn compute_debug_link_crc_of_file_contents<T: FileContents>(
         let chunk_len = CHUNK_SIZE.min(len - offset);
         data.read_bytes_into(&mut buffer, offset, chunk_len as usize)
             .map_err(|e| Error::HelperErrorDuringFileReading("DebugLinkForCrc".to_string(), e))?;
-        computer.consume(&buffer);
+        hasher.update(&buffer);
         buffer.clear();
         offset += CHUNK_SIZE;
     }
-    Ok(computer.0)
+    Ok(hasher.finalize())
 }
 
 async fn try_to_load_supplementary_file<'data, H, F, R>(

wholesym/Cargo.toml

@@ -52,6 +52,14 @@ scopeguard = { version = "1.2.0", default-features = false }
 core-foundation-sys = "0.8"
 core-foundation = "0.10"
 
+# Turn on the zlib-rs feature in flate2.
+# flate2 isn't used directly by wholesym; it's used via async-compression
+# So this is a (somewhat brittle) way to turn on the zlib-rs feature in
+# async-compression's use of flate2.
+[dependencies.flate2]
+version = "1.0.17"
+features = ["zlib-rs"]
+
 [dev-dependencies]
 futures = "0.3.5"
 tokio = { version = "1.38", features = ["macros"] } # Feature "macros" for #[tokio::test]

wholesym/src/breakpad.rs

@@ -273,7 +273,7 @@ impl BreakpadSymbolDownloaderInner {
             .await
             .map_err(SymindexGenerationError::SymReading)?;
         let mut parser = BreakpadIndexParser::new();
-        const CHUNK_SIZE: usize = 4 * 1024 * 1024; // 4MiB
+        const CHUNK_SIZE: usize = 2 * 1024 * 1024; // 2 MiB
         let mut buffer = vec![0; CHUNK_SIZE];
         loop {
             let read_len = sym_file

wholesym/src/downloader.rs

@@ -323,7 +323,7 @@ impl PendingDownload {
             dest_path,
             |dest_file: std::fs::File| async move {
                 let mut dest_file = tokio::fs::File::from_std(dest_file);
-                let mut buf = vec![0u8; 4096];
+                let mut buf = vec![0u8; 2 * 1024 * 1024 /* 2 MiB */];
                 let mut uncompressed_size_in_bytes = 0;
                 loop {
                     let count = stream
@@ -417,7 +417,7 @@ impl PendingDownload {
         let bytes_ref = &mut bytes;
 
         let download_result: Result<u64, std::io::Error> = async move {
-            let mut buf = vec![0u8; 4096];
+            let mut buf = vec![0u8; 2 * 1024 * 1024 /* 2 MiB */];
             let mut uncompressed_size_in_bytes = 0;
             loop {
                 let count = stream.read(&mut buf).await?;