Swap internal numtoa module for external numtoa crate

- I've spun the `numtoa` module off into a new crate
- The new crate contains more performance optimizations
- The `numtoa` crate has the same performance as the `itoa` crate
- Integer conversions have never been better

Cargo.toml

@@ -10,6 +10,7 @@ readme = "README.md"
 
 [dependencies]
 itoa         = "0.1"
+numtoa       = "0.0.3"
 num_cpus     = "1.2"
 permutate    = "0.2"
 arrayvec     = "0.3"

src/execute/dry.rs

@@ -2,7 +2,7 @@ use input_iterator::{InputIterator, InputIteratorErr};
 use tokenizer::Token;
 use arguments;
 use execute::command;
-use misc::NumToA;
+use numtoa::NumToA;
 
 use std::io::{self, StdoutLock, Write};
 
@@ -18,8 +18,8 @@ pub fn dry_run(flags: u16, inputs: InputIterator, arguments: &[Token]) {
     let pipe               = flags & arguments::PIPE_IS_ENABLED != 0;
     let mut id_buffer      = [0u8; 20];
     let mut total_buffer   = [0u8; 20];
-    let truncate           = inputs.total_arguments.numtoa(10, &mut total_buffer);
-    let job_total          = &total_buffer[0..truncate];
+    let start_indice       = inputs.total_arguments.numtoa(10, &mut total_buffer);
+    let job_total          = &total_buffer[start_indice..];
 
     // If `SHELL_QUOTE` is enabled then the quoted command will be printed, otherwise the command will be
     // printed unmodified. The correct function to execute will be assigned here in advance.
@@ -40,10 +40,10 @@ pub fn dry_run(flags: u16, inputs: InputIterator, arguments: &[Token]) {
     for (job_id, input) in inputs.enumerate() {
         match input {
             Ok(input) => {
-                let truncate = job_id.numtoa(10, &mut id_buffer);
+                let start_indice = job_id.numtoa(10, &mut id_buffer);
                 let command = command::ParallelCommand {
                     slot_no:          slot,
-                    job_no:           &id_buffer[0..truncate],
+                    job_no:           &id_buffer[start_indice..],
                     job_total:        job_total,
                     input:            &input,
                     command_template: arguments,

src/execute/exec_commands.rs

@@ -1,7 +1,7 @@
 use arguments::{VERBOSE_MODE, JOBLOG};
 use execute::command::{self, CommandErr};
 use input_iterator::InputsLock;
-use misc::NumToA;
+use numtoa::NumToA;
 use time::{self, Timespec};
 use tokenizer::Token;
 use verbose;
@@ -39,19 +39,19 @@ impl ExecCommands {
         let mut id_buffer      = [0u8; 20];
         let mut job_buffer     = [0u8; 20];
         let mut total_buffer   = [0u8; 20];
-        let truncate           = self.num_inputs.numtoa(10, &mut total_buffer);
-        let job_total          = &total_buffer[0..truncate];
+        let mut start_indice   = self.num_inputs.numtoa(10, &mut total_buffer);
+        let job_total          = &total_buffer[start_indice..];
 
 
         while let Some(job_id) = self.inputs.try_next(&mut input) {
             if self.flags & VERBOSE_MODE != 0  {
                 verbose::processing_task(&stdout, job_id+1, self.num_inputs, &input);
             }
 
-            let truncate = (job_id+1).numtoa(10, &mut id_buffer);
+            start_indice = (job_id+1).numtoa(10, &mut id_buffer);
             let command = command::ParallelCommand {
                 slot_no:          slot,
-                job_no:           &id_buffer[0..truncate],
+                job_no:           &id_buffer[start_indice..],
                 job_total:        job_total,
                 input:            &input,
                 command_template: self.arguments,

src/execute/job_log.rs

@@ -1,5 +1,5 @@
 use arguments::JOBLOG_8601;
-use misc::NumToA;
+use numtoa::NumToA;
 use std::fs::File;
 use std::io::{Write, BufWriter};
 use time::{at, Timespec};
@@ -25,74 +25,77 @@ pub struct JobLog {
 impl JobLog {
     /// Writes an individual job log to the job log file, efficiently.
     pub fn write_entry(&self, joblog: &mut File, id_buffer: &mut [u8], pad: usize) {
+        let mut start_indice;
         // 1: JobID
         let mut joblog = BufWriter::new(joblog);
-        let bytes_written = (self.job_id + 1).numtoa(10, id_buffer);
-        let _ = joblog.write(&id_buffer[0..bytes_written]);
-        for _ in 0..pad-bytes_written {
+        start_indice = (self.job_id + 1).numtoa(10, id_buffer);
+        let _ = joblog.write(&id_buffer[start_indice..]);
+        for _ in 0..pad-id_buffer[start_indice..].len() {
             let _ = joblog.write(b" ");
         }
 
         // 2: StartTime
         if self.flags & JOBLOG_8601 != 0 {
             // ISO 8601 representation of the time
             let tm = at(self.start_time);
+            // TODO: Eliminate heap allocation
             let message = format!("{}-{:02}-{:02} {:02}:{:02}:{:02}  ", 1900+tm.tm_year, 1+tm.tm_mon,
                 tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
             let _ = joblog.write(message.as_bytes());
 
         } else {
             // Represented in seconds, with two decimal places
-            let bytes_written = self.start_time.sec.numtoa(10, id_buffer);
-            let _ = joblog.write(&id_buffer[0..bytes_written]);
+            // TODO: write an abstraction for printing decimals
+            start_indice = self.start_time.sec.numtoa(10, id_buffer);
+            let _ = joblog.write(&id_buffer[start_indice..]);
             let _ = joblog.write(b".");
             let decimal = (self.start_time.nsec % 1_000_000_000) / 1_000_000;
             if decimal == 0 {
                 let _ = joblog.write(b"000");
             } else {
-                let bytes_written = decimal.numtoa(10, id_buffer);
-                match bytes_written {
+                start_indice = decimal.numtoa(10, id_buffer);
+                match id_buffer[start_indice..].len() {
                     1 => { let _ = joblog.write(b"00"); },
                     2 => { let _ = joblog.write(b"0"); },
                     _ => (),
                 };
-                let _ = joblog.write(&id_buffer[0..bytes_written]);
+                let _ = joblog.write(&id_buffer[start_indice..]);
             }
             let _ = joblog.write(b"  ");
         }
 
         // 3: Runtime in seconds, with up to three decimal places.
-        let bytes_written = (self.runtime / 1_000_000_000).numtoa(10, id_buffer);
-        for _ in 0..6-bytes_written {
+        start_indice = (self.runtime / 1_000_000_000).numtoa(10, id_buffer);
+        for _ in 0..6-id_buffer[start_indice..].len() {
             let _ = joblog.write(b" ");
         }
-        let _ = joblog.write(&id_buffer[0..bytes_written]);
+        let _ = joblog.write(&id_buffer[start_indice..]);
         let _ = joblog.write(b".");
         let decimal = (self.runtime % 1_000_000_000) / 1_000_000;
         if decimal == 0 {
             let _ = joblog.write(b"000");
         } else {
-            let bytes_written = decimal.numtoa(10, id_buffer);
-            match bytes_written {
+            start_indice = decimal.numtoa(10, id_buffer);
+            match id_buffer[start_indice..].len() {
                 1 => { let _ = joblog.write(b"00"); },
                 2 => { let _ = joblog.write(b"0"); },
                 _ => (),
             };
-            let _ = joblog.write(&id_buffer[0..bytes_written]);
+            let _ = joblog.write(&id_buffer[start_indice..]);
         }
         let _ = joblog.write(b"  ");
 
         // 4: Exit Value
-        let bytes_written = self.exit_value.numtoa(10, id_buffer);
-        let _ = joblog.write(&id_buffer[0..bytes_written]);
-        for _ in 0..9-bytes_written {
+        start_indice = self.exit_value.numtoa(10, id_buffer);
+        let _ = joblog.write(&id_buffer[start_indice..]);
+        for _ in 0..9-id_buffer[start_indice..].len() {
             let _ = joblog.write(b" ");
         }
 
         // 5: Signal
-        let bytes_written = self.signal.numtoa(10, id_buffer);
-        let _ = joblog.write(&id_buffer[0..bytes_written]);
-        for _ in 0..8-bytes_written {
+        start_indice = self.signal.numtoa(10, id_buffer);
+        let _ = joblog.write(&id_buffer[start_indice..]);
+        for _ in 0..8-id_buffer[start_indice..].len() {
             let _ = joblog.write(b" ");
         }
 

src/filepaths.rs

@@ -1,5 +1,5 @@
+use numtoa::NumToA;
 use std::path::PathBuf;
-use misc::NumToA;
 
 #[cfg(not(windows))]
 pub fn base() -> Option<PathBuf> {
@@ -19,8 +19,8 @@ pub fn new_job(base: &str, id: usize, buffer: &mut [u8]) -> (usize, String, Stri
     let mut stdout = String::from(base) + "/stdout_";
     let mut stderr = String::from(base) + "/stderr_";
     let truncate_value = stdout.len();
-    let length = id.numtoa(10, buffer);
-    for byte in &buffer[0..length] {
+    let start_indice = id.numtoa(10, buffer);
+    for byte in &buffer[start_indice..] {
         stdout.push(*byte as char);
         stderr.push(*byte as char);
     }
@@ -30,8 +30,8 @@ pub fn new_job(base: &str, id: usize, buffer: &mut [u8]) -> (usize, String, Stri
 pub fn next_job_path(id: usize, truncate: usize, buffer: &mut [u8], stdout: &mut String, stderr: &mut String) {
     stdout.truncate(truncate);
     stderr.truncate(truncate);
-    let length = id.numtoa(10, buffer);
-    for byte in &buffer[0..length] {
+    let start_indice = id.numtoa(10, buffer);
+    for byte in &buffer[start_indice..] {
         stdout.push(*byte as char);
         stderr.push(*byte as char);
     }

src/main.rs

@@ -5,6 +5,7 @@
 extern crate alloc_system;
 extern crate arrayvec;
 extern crate itoa;
+extern crate numtoa;
 extern crate num_cpus;
 extern crate permutate;
 extern crate smallvec;

src/misc/mod.rs

@@ -1,10 +1,5 @@
 ///! The purpose of this module is to supply supporting miscellanious traits for use throughout the project.
 mod digits;
-mod numtoa;
 
 /// The `Digits` trait is used to get the number of digits within a number.
 pub use self::digits::Digits;
-
-/// The `NumToA` trait converts integers into their string representation,
-/// but stores the results in a mutable stack-allocated byte slice.
-pub use self::numtoa::NumToA;