# Offers the base 64 encoding and decoding algorithms
module base64
-redef class String
-
+redef class NativeString
# Alphabet used by the base64 algorithm
- private fun base64_chars : String
+ private fun base64_chars : SequenceRead[Byte]
do
- return "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+ return "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".bytes
end
+
+ # Reversed alphabet for base64
private fun inverted_base64_chars : HashMap[Byte, Byte]
do
var inv_base64_chars = new HashMap[Byte, Byte]
- for k in [0..base64_chars.bytelen[ do
- inv_base64_chars[base64_chars.bytes[k]] = k.to_b
+ var l = base64_chars.length
+ for k in [0 .. l[ do
+ inv_base64_chars[base64_chars[k]] = k.to_b
end
return inv_base64_chars
end
- # Encodes the receiver string to base64.
+ # Encodes `self` to base64.
+ #
# By default, uses "=" for padding.
- fun encode_base64 : String do return encode_base64_custom_padding('='.ascii.to_b)
-
- # Encodes the receiver string to base64 using a custom padding character.
#
- # If using the default padding character `=`, see `encode_base64`.
- fun encode_base64_custom_padding(padding : Byte) : String
- do
- var base64_bytes = once base64_chars.bytes
- var length = bytelen
-
+ # assert "string".encode_base64 == "c3RyaW5n"
+ private fun encode_base64(length: Int, padding: nullable Byte): Bytes do
+ var base64_bytes = once base64_chars
+ if padding == null then padding = '='.ascii
var steps = length / 3
var bytes_in_last_step = length % 3
var result_length = steps * 4
if bytes_in_last_step > 0 then result_length += 4
- var result = new NativeString(result_length + 1)
- var bytes = self.bytes
- result[result_length] = 0u8
-
- var mask_6bit = 0b0011_1111
+ var result = new Bytes.with_capacity(result_length)
+ var in_off = 0
for s in [0 .. steps[ do
- var e = 0
- for ss in [0 .. 3[ do
- e += bytes[s * 3 + ss].to_i << ((2 - ss) * 8)
- end
- for ss in [0..4[ do
- result[s * 4 + 3 - ss] = base64_bytes[(e >> (ss * 6)) & mask_6bit]
- end
+ var ind = ((self[in_off] & 0b1111_1100u8) >> 2).to_i
+ result.add base64_bytes[ind]
+ ind = ((self[in_off] & 0b0000_0011u8) << 4).to_i | ((self[in_off + 1] & 0b1111_0000u8) >> 4).to_i
+ result.add base64_bytes[ind]
+ ind = ((self[in_off + 1] & 0b0000_1111u8) << 2).to_i | ((self[in_off + 2] & 0b1100_0000u8) >> 6).to_i
+ result.add base64_bytes[ind]
+ ind = (self[in_off + 2] & 0b0011_1111u8).to_i
+ result.add base64_bytes[ind]
+ in_off += 3
end
-
- var out_off = result_length - 4
- var in_off = length - bytes_in_last_step
if bytes_in_last_step == 1 then
- result[out_off] = base64_bytes[((bytes[in_off] & 0b1111_1100u8) >> 2).to_i]
- result[out_off + 1] = base64_bytes[((bytes[in_off] & 0b0000_0011u8) << 4).to_i]
- out_off += 2
+ result.add base64_bytes[((self[in_off] & 0b1111_1100u8) >> 2).to_i]
+ result.add base64_bytes[((self[in_off] & 0b0000_0011u8) << 4).to_i]
else if bytes_in_last_step == 2 then
- result[out_off] = base64_bytes[((bytes[in_off] & 0b1111_1100u8) >> 2).to_i]
- result[out_off + 1] = base64_bytes[(((bytes[in_off] & 0b0000_0011u8) << 4) | ((bytes[in_off + 1] & 0b1111_0000u8) >> 4)).to_i]
- result[out_off + 2] = base64_bytes[((bytes[in_off + 1] & 0b0000_1111u8) << 2).to_i]
- out_off += 3
- end
- if bytes_in_last_step > 0 then
- for i in [out_off .. result_length[ do result[i] = padding
+ result.add base64_bytes[((self[in_off] & 0b1111_1100u8) >> 2).to_i]
+ result.add base64_bytes[(((self[in_off] & 0b0000_0011u8) << 4) | ((self[in_off + 1] & 0b1111_0000u8) >> 4)).to_i]
+ result.add base64_bytes[((self[in_off + 1] & 0b0000_1111u8) << 2).to_i]
end
+ var rempad = if bytes_in_last_step > 0 then 3 - bytes_in_last_step else 0
+ for i in [0 .. rempad[ do result.add padding
- return result.to_s_with_length(result_length)
+ return result
end
- # Decodes the receiver string from base64.
- # By default, uses "=" for padding.
- fun decode_base64 : String do return decode_base64_custom_padding('='.ascii.to_b)
-
- # Decodes the receiver string to base64 using a custom padding character.
+ # Decodes `self` from base64
#
- # If using the default padding character `=`, see `decode_base64`.
- fun decode_base64_custom_padding(padding : Byte) : String
- do
+ # assert "c3RyaW5n".decode_base64 == "string"
+ #
+ # REQUIRE: `length % 4 == 0`
+ private fun decode_base64(length: Int, padding: nullable Byte): Bytes do
+ if padding == null then padding = '='.ascii
var inv = once inverted_base64_chars
- var length = bytelen
- if length == 0 then return ""
+ if length == 0 then return new Bytes.empty
assert length % 4 == 0 else print "base64::decode_base64 only supports strings of length multiple of 4"
- var bytes = self.bytes
+ var bytes = self
var steps = length / 4
var result_length = steps * 3
if padding_len == 1 then result_length -= 1
if padding_len == 2 then result_length -= 2
- var result = new NativeString(result_length + 1)
- result[result_length] = 0u8
+ var result = new Bytes.with_capacity(result_length + 1)
for s in [0 .. steps[ do
var c0 = inv[bytes[s * 4]]
var c1 = inv[bytes[s * 4 + 1]]
var c2 = inv[bytes[s * 4 + 2]]
var c3 = inv[bytes[s * 4 + 3]]
- result[s * 3] = ((c0 & 0b0011_1111u8) << 2) | ((c1 & 0b0011_0000u8) >> 4)
- result[s * 3 + 1] = ((c1 & 0b0000_1111u8) << 4) | ((c2 & 0b0011_1100u8) >> 2)
- result[s * 3 + 2] = ((c2 & 0b0000_0011u8) << 6) | (c3 & 0b0011_1111u8)
+ result.add (((c0 & 0b0011_1111u8) << 2) | ((c1 & 0b0011_0000u8) >> 4))
+ result.add (((c1 & 0b0000_1111u8) << 4) | ((c2 & 0b0011_1100u8) >> 2))
+ result.add (((c2 & 0b0000_0011u8) << 6) | (c3 & 0b0011_1111u8))
end
var last_start = steps * 4
var c0 = inv[bytes[last_start]]
var c1 = inv[bytes[last_start + 1]]
var c2 = inv[bytes[last_start + 2]]
- result[result_length - 2] = ((c0 & 0b0011_1111u8) << 2) | ((c1 & 0b0011_0000u8) >> 4)
- result[result_length - 1] = ((c1 & 0b0000_1111u8) << 4) | ((c2 & 0b0011_1100u8) >> 2)
+ result.add (((c0 & 0b0011_1111u8) << 2) | ((c1 & 0b0011_0000u8) >> 4))
+ result.add (((c1 & 0b0000_1111u8) << 4) | ((c2 & 0b0011_1100u8) >> 2))
else if padding_len == 2 then
var c0 = inv[bytes[last_start]]
var c1 = inv[bytes[last_start + 1]]
- result[result_length - 1] = ((c0 & 0b0011_1111u8) << 2) | ((c1 & 0b0011_0000u8) >> 4)
+ result.add (((c0 & 0b0011_1111u8) << 2) | ((c1 & 0b0011_0000u8) >> 4))
end
- return result.to_s_with_length(result_length)
+ return result
+ end
+end
+
+redef class Bytes
+
+ # Encodes the receiver string to base64 using a custom padding character.
+ #
+ # If using the default padding character `=`, see `encode_base64`.
+ fun encode_base64(padding: nullable Byte): Bytes
+ do
+ return items.encode_base64(length, padding)
+ end
+
+ # Decodes the receiver string to base64 using a custom padding character.
+ #
+ # Default padding character `=`
+ fun decode_base64(padding : nullable Byte) : Bytes
+ do
+ return items.decode_base64(length, padding)
+ end
+end
+
+redef class String
+
+ # Encodes the receiver string to base64 using a custom padding character.
+ #
+ # If using the default padding character `=`, see `encode_base64`.
+ fun encode_base64(padding: nullable Byte): String
+ do
+ return to_cstring.encode_base64(bytelen, padding).to_s
+ end
+
+ # Decodes the receiver string to base64 using a custom padding character.
+ #
+ # Default padding character `=`
+ fun decode_base64(padding : nullable Byte) : String
+ do
+ return to_cstring.decode_base64(bytelen, padding).to_s
end
end
nitlanguage / nit.git / blobdiff