fix shuf

src/shuf/deps.mk

@@ -0,0 +1 @@
+DEPLIBS += rand

src/shuf/shuf.rs

@@ -1,5 +1,5 @@
 #![crate_name = "shuf"]
-#![feature(collections, core, old_io, old_path, rand, rustc_private)]
+#![feature(rustc_private)]
 
 /*
  * This file is part of the uutils coreutils package.
@@ -12,13 +12,13 @@
 
 extern crate getopts;
 extern crate libc;
+extern crate rand;
 
-use std::cmp;
-use std::old_io as io;
-use std::old_io::IoResult;
-use std::iter::{range_inclusive, RangeInclusive};
-use std::rand::{self, Rng};
-use std::usize;
+use rand::read::ReadRng;
+use rand::{Rng, ThreadRng};
+use std::fs::File;
+use std::io::{stdin, stdout, BufReader, BufWriter, Read, Write};
+use std::usize::MAX as MAX_USIZE;
 
 #[path = "../common/util.rs"]
 #[macro_use]
@@ -27,15 +27,13 @@ mod util;
 enum Mode {
     Default,
     Echo,
-    InputRange(RangeInclusive<usize>)
+    InputRange((usize, usize))
 }
 
 static NAME: &'static str = "shuf";
 static VERSION: &'static str = "0.0.1";
 
 pub fn uumain(args: Vec<String>) -> i32 {
-    let program = args[0].clone();
-
     let opts = [
         getopts::optflag("e", "echo", "treat each ARG as an input line"),
         getopts::optopt("i", "input-range", "treat each number LO through HI as an input line", "LO-HI"),
@@ -47,7 +45,7 @@ pub fn uumain(args: Vec<String>) -> i32 {
         getopts::optflag("h", "help", "display this help and exit"),
         getopts::optflag("V", "version", "output version information and exit")
     ];
-    let mut matches = match getopts::getopts(args.tail(), &opts) {
+    let mut matches = match getopts::getopts(&args[1..], &opts) {
         Ok(m) => m,
         Err(f) => {
             crash!(1, "{}", f)
@@ -62,7 +60,7 @@ Usage:
   {prog} -i LO-HI [OPTION]...\n
 {usage}
 With no FILE, or when FILE is -, read standard input.",
-                 name = NAME, version = VERSION, prog = program,
+                 name = NAME, version = VERSION, prog = &args[0][..],
                  usage = getopts::usage("Write a random permutation of the input lines to standard output.", &opts));
     } else if matches.opt_present("version") {
         println!("{} v{}", NAME, VERSION);
@@ -76,10 +74,9 @@ With no FILE, or when FILE is -, read standard input.",
                 }
                 match parse_range(range) {
                     Ok(m) => Mode::InputRange(m),
-                    Err((msg, code)) => {
-                        show_error!("{}", msg);
-                        return code;
-                    }
+                    Err(msg) => {
+                        crash!(1, "{}", msg);
+                    },
                 }
             }
             None => {
@@ -88,13 +85,19 @@ With no FILE, or when FILE is -, read standard input.",
                 } else {
                     if matches.free.len() == 0 {
                         matches.free.push("-".to_string());
+                    } else if matches.free.len() > 1 {
+                        show_error!("extra operand '{}'", &matches.free[1][..]);
                     }
                     Mode::Default
                 }
             }
         };
         let repeat = matches.opt_present("repeat");
-        let zero = matches.opt_present("zero-terminated");
+        let sep = if matches.opt_present("zero-terminated") {
+            0x00 as u8
+        } else {
+            0x0a as u8
+        };
         let count = match matches.opt_str("head-count") {
             Some(cnt) => match cnt.parse::<usize>() {
                 Ok(val) => val,
@@ -103,102 +106,166 @@ With no FILE, or when FILE is -, read standard input.",
                     return 1;
                 }
             },
-            None => usize::MAX
+            None => MAX_USIZE,
         };
         let output = matches.opt_str("output");
         let random = matches.opt_str("random-source");
-        match shuf(matches.free, mode, repeat, zero, count, output, random) {
-            Err(f) => {
-                show_error!("{}", f);
-                return 1;
+
+        match mode {
+            Mode::Echo => {
+                // XXX: this doesn't correctly handle non-UTF-8 cmdline args
+                let mut evec = matches.free.iter().map(|a| a.as_bytes()).collect::<Vec<&[u8]>>();
+                find_seps(&mut evec, sep);
+                shuf_bytes(&mut evec, repeat, count, sep, output, random);
             },
-            _ => {}
+            Mode::InputRange((b, e)) => {
+                let rvec = (b..e).map(|x| format!("{}", x)).collect::<Vec<String>>();
+                let mut rvec = rvec.iter().map(|a| a.as_bytes()).collect::<Vec<&[u8]>>();
+                shuf_bytes(&mut rvec, repeat, count, sep, output, random);
+            },
+            Mode::Default => {
+                let fdata = read_input_file(&matches.free[0][..]);
+                let mut fdata = vec!(&fdata[..]);
+                find_seps(&mut fdata, sep);
+                shuf_bytes(&mut fdata, repeat, count, sep, output, random);
+            }
         }
     }
 
     0
 }
 
-fn shuf(input: Vec<String>, mode: Mode, repeat: bool, zero: bool, count: usize, output: Option<String>, random: Option<String>) -> IoResult<()> {
-    match mode {
-        Mode::Echo => shuf_lines(input, repeat, zero, count, output, random),
-        Mode::InputRange(range) => shuf_lines(range.map(|num| num.to_string()).collect(), repeat, zero, count, output, random),
-        Mode::Default => {
-            let lines: Vec<String> = input.into_iter().flat_map(|filename| {
-                let slice = filename.as_slice();
-                let mut file_buf;
-                let mut stdin_buf;
-                let mut file = io::BufferedReader::new(
-                    if slice == "-" {
-                        stdin_buf = io::stdio::stdin_raw();
-                        &mut stdin_buf as &mut Reader
+fn read_input_file(filename: &str) -> Vec<u8> {
+    let mut file = BufReader::new(
+        if filename == "-" {
+            Box::new(stdin()) as Box<Read>
         } else {
-                        file_buf = crash_if_err!(1, io::File::open(&Path::new(slice)));
-                        &mut file_buf as &mut Reader
+            match File::open(filename) {
+                Ok(f) => Box::new(f) as Box<Read>,
+                Err(e) => crash!(1, "failed to open '{}': {}", filename, e),
             }
-                );
-                let mut lines = vec!();
-                for line in file.lines() {
-                    let mut line = crash_if_err!(1, line);
-                    line.pop();
-                    lines.push(line);
+        });
+
+    let mut data = Vec::new();
+    match file.read_to_end(&mut data) {
+        Err(e) => crash!(1, "failed reading '{}': {}", filename, e),
+        Ok(_) => (),
+    };
+
+    data
 }
-                lines.into_iter()
-            }).collect();
-            shuf_lines(lines, repeat, zero, count, output, random)
+
+fn find_seps(data: &mut Vec<&[u8]>, sep: u8) {
+    // need to use for loop so we don't borrow the vector as we modify it in place
+    // basic idea:
+    // * We don't care about the order of the result. This lets us slice the slices
+    //   without making a new vector.
+    // * Starting from the end of the vector, we examine each element.
+    // * If that element contains the separator, we remove it from the vector,
+    //   and then sub-slice it into slices that do not contain the separator.
+    // * We maintain the invariant throughout that each element in the vector past
+    //   the ith element does not have any separators remaining.
+    for i in (0..data.len()).rev() {
+        if data[i].contains(&sep) {
+            let this = data.swap_remove(i);
+            let mut p = 0;
+            let mut i = 1;
+            loop {
+                if i == this.len() {
+                    break;
                 }
+
+                if this[i] == sep {
+                    data.push(&this[p..i]);
+                    p = i + 1;
+                }
+                i += 1;
+            }
+            if p < this.len() {
+                data.push(&this[p..i]);
+            }
+        }
+    }
+}
+
+fn shuf_bytes(input: &mut Vec<&[u8]>, repeat: bool, count: usize, sep: u8, output: Option<String>, random: Option<String>) {
+    let mut output = BufWriter::new(
+        match output {
+            None => Box::new(stdout()) as Box<Write>,
+            Some(s) => match File::create(&s[..]) {
+                Ok(f) => Box::new(f) as Box<Write>,
+                Err(e) => crash!(1, "failed to open '{}' for writing: {}", &s[..], e),
+            },
+        });
+
+    let mut rng = match random {
+        Some(r) => WrappedRng::RngFile(rand::read::ReadRng::new(match File::open(&r[..]) {
+            Ok(f) => f,
+            Err(e) => crash!(1, "failed to open random source '{}': {}", &r[..], e),
+        })),
+        None => WrappedRng::RngDefault(rand::thread_rng()),
+    };
+
+    // we're generating a random usize. To keep things fair, we take this number mod ceil(log2(length+1))
+    let mut len_mod = 1;
+    let mut len = input.len();
+    while len > 0 {
+        len >>= 1;
+        len_mod <<= 1;
+    }
+    drop(len);
+
+    let mut count = count;
+    while count > 0 && input.len() > 0 {
+        let mut r = input.len();
+        while r >= input.len() {
+            r = rng.next_usize() % len_mod;
+        }
+
+        // write the randomly chosen value and the separator
+        output.write_all(input[r]).unwrap_or_else(|e| crash!(1, "write failed: {}", e));
+        output.write_all(&[sep]).unwrap_or_else(|e| crash!(1, "write failed: {}", e));
+
+        // if we do not allow repeats, remove the chosen value from the input vector
+        if !repeat {
+            // shrink the mask if we will drop below a power of 2
+            if input.len() % 2 == 0 && len_mod > 2 {
+                len_mod >>= 1;
+            }
+            input.swap_remove(r);
+        }
+
+        count -= 1;
+    }
+}
+
+fn parse_range(input_range: String) -> Result<(usize, usize), String> {
+    let split: Vec<&str> = input_range.split('-').collect();
+    if split.len() != 2 {
+        Err("invalid range format".to_string())
+    } else {
+        let begin = match split[0].parse::<usize>() {
+            Ok(m) => m,
+            Err(e)=> return Err(format!("{} is not a valid number: {}", split[0], e)),
+        };
+        let end = match split[1].parse::<usize>() {
+            Ok(m) => m,
+            Err(e)=> return Err(format!("{} is not a valid number: {}", split[1], e)),
+        };
+        Ok((begin, end + 1))
     }
 }
 
 enum WrappedRng {
-    RngFile(rand::reader::ReaderRng<io::File>),
+    RngFile(rand::read::ReadRng<File>),
     RngDefault(rand::ThreadRng),
 }
 
 impl WrappedRng {
-    fn next_u32(&mut self) -> u32 {
+    fn next_usize(&mut self) -> usize {
         match self {
-            &mut WrappedRng::RngFile(ref mut r) => r.next_u32(),
-            &mut WrappedRng::RngDefault(ref mut r) => r.next_u32(),
+            &mut WrappedRng::RngFile(ref mut r) => r.next_u32() as usize,
+            &mut WrappedRng::RngDefault(ref mut r) => r.next_u32() as usize,
         }
     }
 }
-
-fn shuf_lines(mut lines: Vec<String>, repeat: bool, zero: bool, count: usize, outname: Option<String>, random: Option<String>) -> IoResult<()> {
-    let mut output = match outname {
-        Some(name) => Box::new(io::BufferedWriter::new(try!(io::File::create(&Path::new(name))))) as Box<Writer>,
-        None => Box::new(io::stdout()) as Box<Writer>
-    };
-    let mut rng = match random {
-        Some(name) => WrappedRng::RngFile(rand::reader::ReaderRng::new(try!(io::File::open(&Path::new(name))))),
-        None => WrappedRng::RngDefault(rand::thread_rng()),
-    };
-    let mut len = lines.len();
-    let max = if repeat { count } else { cmp::min(count, len) };
-    for _ in range(0, max) {
-        let idx = rng.next_u32() as usize % len;
-        try!(write!(output, "{}{}", lines[idx], if zero { '\0' } else { '\n' }));
-        if !repeat {
-            lines.remove(idx);
-            len -= 1;
-        }
-    }
-    Ok(())
-}
-
-fn parse_range(input_range: String) -> Result<RangeInclusive<usize>, (String, i32)> {
-    let split: Vec<&str> = input_range.as_slice().split('-').collect();
-    if split.len() != 2 {
-        Err(("invalid range format".to_string(), 1))
-    } else {
-        let begin = match split[0].parse::<usize>() {
-            Ok(m) => m,
-            Err(e)=> return Err((format!("{} is not a valid number: {}", split[0], e), 1))
-        };
-        let end = match split[1].parse::<usize>() {
-            Ok(m) => m,
-            Err(e)=> return Err((format!("{} is not a valid number: {}", split[1], e), 1))
-        };
-        Ok(range_inclusive(begin, end))
-    }
-}