More perf tweaks (issue #2719)

Author: eholk

src/libcore/dvec.rs

@@ -161,7 +161,6 @@ impl extensions<A> for dvec<A> {
         vec::push(self.data, t);
     }
 
-
     #[doc = "Remove and return the first element"]
     fn shift() -> A {
         self.borrow { |v|

src/libcore/io.rs

@@ -52,7 +52,7 @@ impl reader_util for reader {
                 i += 1u;
                 assert (w > 0u);
                 if w == 1u {
-                    chars += [ b0 as char ]/~;
+                    vec::push(chars,  b0 as char );
                     cont;
                 }
                 // can't satisfy this char with the existing data
@@ -71,7 +71,7 @@ impl reader_util for reader {
                 // See str::char_at
                 val += ((b0 << ((w + 1u) as u8)) as uint)
                     << (w - 1u) * 6u - w - 1u;
-                chars += [ val as char ]/~;
+                vec::push(chars,  val as char );
             }
             ret (i, 0u);
         }
@@ -86,7 +86,7 @@ impl reader_util for reader {
                 // we're split in a unicode char?
                 break;
             }
-            buf += data;
+            vec::push_all(buf, data);
             let (offset, nbreq) = chars_from_buf(buf, chars);
             let ncreq = n - vec::len(chars);
             // again we either know we need a certain number of bytes
@@ -110,11 +110,11 @@ impl reader_util for reader {
     }
 
     fn read_line() -> str {
-        let mut buf: [u8]/~ = []/~;
+        let mut buf = []/~;
         loop {
             let ch = self.read_byte();
             if ch == -1 || ch == 10 { break; }
-            buf += [ch as u8]/~;
+            vec::push(buf, ch as u8);
         }
         str::from_bytes(buf)
     }
@@ -123,7 +123,7 @@ impl reader_util for reader {
         let mut buf: [u8]/~ = []/~;
         loop {
             let ch = self.read_byte();
-            if ch < 1 { break; } else { buf += [ch as u8]/~; }
+            if ch < 1 { break; } else { vec::push(buf, ch as u8); }
         }
         str::from_bytes(buf)
     }
@@ -158,7 +158,7 @@ impl reader_util for reader {
 
     fn read_whole_stream() -> [u8]/~ {
         let mut buf: [u8]/~ = []/~;
-        while !self.eof() { buf += self.read_bytes(2048u); }
+        while !self.eof() { vec::push_all(buf, self.read_bytes(2048u)); }
         buf
     }
 
@@ -453,7 +453,7 @@ fn u64_to_le_bytes<T>(n: u64, size: uint, f: fn([u8]/&) -> T) -> T {
 
         let mut bytes: [u8]/~ = []/~, i = size, n = n;
         while i > 0u {
-            bytes += [(n & 255_u64) as u8]/~;
+            vec::push(bytes, (n & 255_u64) as u8);
             n >>= 8_u64;
             i -= 1u;
         }
@@ -485,7 +485,7 @@ fn u64_to_be_bytes<T>(n: u64, size: uint, f: fn([u8]/&) -> T) -> T {
         let mut i = size;
         while i > 0u {
             let shift = ((i - 1u) * 8u) as u64;
-            bytes += [(n >> shift) as u8]/~;
+            vec::push(bytes, (n >> shift) as u8);
             i -= 1u;
         }
         f(bytes)

src/libcore/str.rs

@@ -122,7 +122,7 @@ Convert a vector of bytes to a UTF-8 string
 
 Fails if invalid UTF-8
 "]
-pure fn from_bytes(vv: [u8]/~) -> str {
+pure fn from_bytes(+vv: [u8]/~) -> str {
     assert is_utf8(vv);
     ret unsafe { unsafe::from_bytes(vv) };
 }
@@ -1750,9 +1750,9 @@ mod unsafe {
 
    Does not verify that the vector contains valid UTF-8.
    "]
-   unsafe fn from_bytes(v: [const u8]/~) -> str {
+   unsafe fn from_bytes(+v: [const u8]/~) -> str {
        unsafe {
-           let mut vcopy = ::unsafe::transmute(copy v);
+           let mut vcopy = ::unsafe::transmute(v);
            vec::push(vcopy, 0u8);
            ::unsafe::transmute(vcopy)
        }

src/libcore/vec.rs

@@ -384,13 +384,12 @@ fn shift<T>(&v: [T]/~) -> T {
         let mut rr;
         {
             let vv = unsafe::to_ptr(vv);
-            let mut r <- *vv;
+            rr <- *vv;
 
             for uint::range(1u, ln) {|i|
                 let r <- *ptr::offset(vv, i);
                 push(v, r);
             }
-            rr <- r;
         }
         unsafe::set_len(vv, 0u);
 

src/test/bench/core-std.rs

@@ -0,0 +1,48 @@
+// Microbenchmarks for various functions in core and std
+
+use std;
+
+import std::time::precise_time_s;
+
+import io::{reader, reader_util};
+
+fn main() {
+    #macro[
+        [#bench[id],
+         run_test(#stringify(id), id)]
+    ];
+
+    #bench[shift_push];
+    #bench[read_line];
+}
+
+fn run_test(name: str, test: fn()) {
+    let start = precise_time_s();
+    test();
+    let stop = precise_time_s();
+
+    io::println(#fmt("%s:\t\t%f ms", name, (stop - start) * 1000f));
+}
+
+fn shift_push() {
+    let mut v1 = vec::from_elem(30000, 1);
+    let mut v2 = []/~;
+
+    while v1.len() > 0 {
+        vec::push(v2, vec::shift(v1));
+    }
+}
+
+fn read_line() {
+    let path = path::connect(
+        #env("CFG_SRC_DIR"),
+        "src/test/bench/shootout-k-nucleotide.data"
+    );
+
+    for int::range(0, 3) {|_i|
+        let reader = result::get(io::file_reader(path));
+        while !reader.eof() {
+            reader.read_line();
+        }
+    }
+}

src/test/bench/shootout-k-nucleotide.rs

@@ -62,29 +62,32 @@ fn find(mm: hashmap<[u8]/~, uint>, key: str) -> uint {
 }
 
 // given a map, increment the counter for a key
-fn update_freq(mm: hashmap<[u8]/~, uint>, key: [u8]/~) {
-   alt mm.find(key) {
+fn update_freq(mm: hashmap<[u8]/~, uint>, key: [u8]/&) {
+    let key = vec::slice(key, 0, key.len());
+    alt mm.find(key) {
       option::none      { mm.insert(key, 1u      ); }
       option::some(val) { mm.insert(key, 1u + val); }
-   }
+    }
 }
 
 // given a [u8]/~, for each window call a function
 // i.e., for "hello" and windows of size four,
 // run it("hell") and it("ello"), then return "llo"
-fn windows_with_carry(bb: [const u8]/~, nn: uint, it: fn(window: [u8]/~)) -> [u8]/~ {
+fn windows_with_carry(bb: [const u8]/~, nn: uint,
+                      it: fn(window: [u8]/&)) -> [u8]/~ {
    let mut ii = 0u;
 
    let len = vec::len(bb);
    while ii < len - (nn - 1u) {
-      it(vec::slice(bb, ii, ii+nn));
+      it(vec::view(bb, ii, ii+nn));
       ii += 1u;
    }
 
    ret vec::slice(bb, len - (nn - 1u), len); 
 }
 
-fn make_sequence_processor(sz: uint, from_parent: comm::port<[u8]/~>, to_parent: comm::chan<str>) {
+fn make_sequence_processor(sz: uint, from_parent: comm::port<[u8]/~>,
+                           to_parent: comm::chan<str>) {
 
    let freqs: hashmap<[u8]/~, uint> = map::bytes_hash();
    let mut carry: [u8]/~ = []/~;