Use String.build instead of IO::Memory.

README.md

@@ -1,18 +1,21 @@
 # base32
-
-[![Build Status](https://travis-ci.org/noumar/base32.svg?branch=master)](https://travis-ci.org/noumar/base32)
-[![Docs](http://docrystal.org/badge.svg?style=round)](http://docrystal.org/github.com/noumar/base32)
+[![Crystal CI](https://github.com/didactic-drunk/base32/actions/workflows/crystal.yml/badge.svg)](https://github.com/didactic-drunk/base32/actions/workflows/crystal.yml)
+[![GitHub release](https://img.shields.io/github/release/didactic-drunk/base32.svg)](https://github.com/didactic-drunk/base32/releases)
+![GitHub commits since latest release (by date) for a branch](https://img.shields.io/github/commits-since/didactic-drunk/base32/latest)
+[![Docs](https://img.shields.io/badge/docs-available-brightgreen.svg)](https://didactic-drunk.github.io/base32/master)
 
 Provides encoding and decoding of base32 and base32hex as defined in RFC 4648.
 
+Maintained here temporarily (or permanently) until @noumar returns.
+
 ## Installation
 
 Add this to your application's `shard.yml`:
 
 ```yaml
 dependencies:
   base32:
-    github: noumar/base32
+    github: didactic-drunk/base32
 ```
 
 ## Usage
@@ -33,12 +36,13 @@ TODO: Write development instructions here
 
 ## Contributing
 
-1. Fork it ( https://github.com/noumar/base32/fork )
+1. Fork it ( https://github.com/didactic-drunk/base32/fork )
 2. Create your feature branch (git checkout -b my-new-feature)
 3. Commit your changes (git commit -am 'Add some feature')
 4. Push to the branch (git push origin my-new-feature)
 5. Create a new Pull Request
 
 ## Contributors
 
-- [noumar](https://github.com/noumar) / Mikael Karlsson - creator, maintainer
+- [noumar](https://github.com/noumar) / Mikael Karlsson - creator
+- [didactic-drunk](https://github.com/didactic-drunk) - current maintainer

spec/base32_spec.cr

@@ -12,6 +12,9 @@ describe Base32 do
     Base32.encode("foobar").should eq("MZXW6YTBOI======")
 
     Base32.encode("Hello World!").should eq("JBSWY3DPEBLW64TMMQQQ====")
+
+    # Compared with Ruby version
+    Base32.encode(Bytes.new(4)).should eq("AAAAAAA=")
   end
 
   it "encodes to base32 (w/o padding)" do
@@ -89,4 +92,17 @@ describe Base32 do
     Base32.hex_decode_string("CPNMUOJ1").should eq("fooba")
     Base32.hex_decode_string("CPNMUOJ1E8").should eq("foobar")
   end
+
+  describe "NUL byte" do
+    str = "\0foo\0bar\0"
+    bstr = "ABTG63YAMJQXEAA="
+
+    it "encode" do
+      Base32.encode(str).should eq bstr
+    end
+
+    it "decode" do
+      Base32.decode_string(bstr).should eq str
+    end
+  end
 end

src/base32.cr

@@ -32,65 +32,57 @@ module Base32
 
   # :nodoc:
   private def to_base32(data, pad : Bool, chars : Array(Char)) : String
-    mio = IO::Memory.new((data.bytesize / 5) * 8)
-
-    data.to_slice.each_slice(5) do |slice|
-      bits = 0_u64
-      0.to(slice.size - 1) do |j|
-        bits = bits | (slice[j].to_u64 << (4 - j)*8)
+    ssize = data.bytesize * 8 // 5
+    ssize += 7 if pad
+    String.build(ssize) do |sb|
+      bits = 0
+      b = 0
+      data.to_slice.each do |c|
+        b = (b << 8) | c
+        bits += 8
+        while bits >= 5
+          bits -= 5
+          sb << chars[b >> bits]
+          mask = (1 << bits) - 1
+          b &= mask
+        end
       end
 
-      mask = 0x1F_u64 << 35
-      7.to(0) do |i|
-        num = (bits & mask) >> i*5
-        mio << chars[num]
-        mask = (mask >> 5)
+      if bits > 0
+        sb << chars[b << (5 - bits)]
       end
-    end
 
-    # Exclude empty trailing chars
-    while mio.buffer[mio.pos - 1] == chars[0].ord
-      mio.pos -= 1
-    end
-
-    # Fill with padding
-    until (mio.pos % 8 == 0)
-      mio << PAD
+      if pad
+        rem = sb.bytesize % 8
+        (8 - rem).times { sb << PAD } if rem > 0
+      end
     end
-
-    # Exclude padding if not wanted
-    sl = mio.to_slice
-    while sl[-1] == PAD.ord
-      sl = sl[0, sl.size - 1]
-    end if sl.size > 0 && pad == false
-
-    String.new(sl)
   end
 
+  IGNORE_CHARS = ['\n'.ord, '\r'.ord, '='.ord]
+
   # :nodoc:
-  private def from_base32(data, map : Hash(Char, Int)) : Slice(UInt8)
-    mio = IO::Memory.new((data.bytesize / 8) * 5)
+  private def from_base32(data, map : Hash(Char, Int)) : Bytes
+    mio = IO::Memory.new((data.bytesize // 8) * 5)
 
-    data.to_slice.select { |s| !['\n'.ord, '\r'.ord, '='.ord].includes?(s) }.each_slice(8) do |slice|
+    data.to_slice.select { |s| !IGNORE_CHARS.includes?(s) }.each_slice(8) do |slice|
       bits = 0_u64
-      0.to(slice.size - 1) do |j|
-        bits = bits | (map[slice[j].chr].to_u64 << (7 - j)*5)
+      slice.each_with_index do |b, j|
+        bits = bits | (map[b.chr].to_u64 << (7 - j)*5)
       end
 
       mask = 0xFF_u64 << 32
-      4.to(0) do |i|
+
+      rem_bytes = slice.size * 5 // 8
+
+      4.downto(5 - rem_bytes) do |i|
         num = (bits & mask) >> i*8
         mio.write_byte(num.to_u8)
         mask = (mask >> 8)
       end
     end
 
-    # Exclude trailing zero bytes
-    sl = mio.to_slice
-    while sl[-1] == 0
-      sl = sl[0, sl.size - 1]
-    end if sl.size > 0
-    sl
+    mio.to_slice
   end
 
   # Encode data as base32 with padding, or without if `pad` = false
@@ -99,7 +91,7 @@ module Base32
   end
 
   # Decode base32 data, regardless if padded or not
-  def decode(data) : Slice(UInt8)
+  def decode(data) : Bytes
     from_base32(data, DEC_STD)
   end
 
@@ -114,7 +106,7 @@ module Base32
   end
 
   # Decode base32hex data, regardless if padded or not
-  def hex_decode(data) : Slice(UInt8)
+  def hex_decode(data) : Bytes
     from_base32(data, DEC_HEX)
   end