+++ /dev/null
-# This file is part of NIT ( http://www.nitlanguage.org ).
-#
-# Copyright 2013 Alexis Laferrière <alexis.laf@xymus.net>
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# Offers the base 64 encoding and decoding algorithms
-module base64
-
-redef class Char
- # Is `self` a valid Base64 character ?
- fun is_base64_char: Bool do
- if code_point >= 127 then return false
- return ascii.is_base64_char
- end
-end
-
-redef class Byte
- # Is `self` a valid Base64 character ?
- fun is_base64_char: Bool do
- if self == b'+' then return true
- if self == b'/' then return true
- if self > b'Z' then
- if self < b'a' then return false
- if self <= b'z' then return true
- return false
- end
- if self >= b'A' then return true
- if self <= b'9' and self >= b'0' then return true
- return false
- end
-
- # Returns the `base64` equivalent of `self`
- #
- # REQUIRE `self`.`is_base64_char`
- fun to_base64_char: Byte do
- if self == b'+' then return 62u8
- if self == b'/' then return 63u8
- if self > b'Z' then
- if self < b'a' then abort
- if self <= b'z' then return self - 71u8
- abort
- end
- if self >= b'A' then return self - 0x41u8
- if self <= b'9' and self >= b'0' then return self + 4u8
- abort
- end
-end
-
-redef class CString
- # Alphabet used by the base64 algorithm
- private fun base64_chars : Bytes
- do
- return b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
- end
-
- # Encodes `self` to base64.
- #
- # By default, uses "=" for padding.
- #
- # assert "string".encode_base64 == "c3RyaW5n"
- private fun encode_base64(length: Int): Bytes do
- var base64_bytes = once base64_chars
- 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 Bytes.with_capacity(result_length)
-
- var in_off = 0
- for s in [0 .. steps[ do
- 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
- if bytes_in_last_step == 1 then
- 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.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 b'='
-
- return result
- end
-
- # Decodes `self` from base64
- #
- # assert "c3RyaW5n".decode_base64.to_s == "string"
- # assert "c3Rya\nW5n".decode_base64.to_s == "string"
- # assert "c3RyaW5nCg==".decode_base64.to_s == "string\n"
- # assert "c3RyaW5nCg".decode_base64.to_s == "string\n"
- # assert "c3RyaW5neQo=".decode_base64.to_s == "stringy\n"
- # assert "c3RyaW5neQo".decode_base64.to_s == "stringy\n"
- #
- private fun decode_base64(length: Int): Bytes do
- if length == 0 then return new Bytes.empty
-
- # Avoids constant unboxing
- var pad = b'='
-
- var result = new Bytes.with_capacity((length / 4 + 1) * 3)
-
- var curr = 0
- var cnt = 0
- var endpos = -1
- for i in [0 .. length[ do
- var b = self[i]
- if b == pad then
- endpos = i
- break
- end
- # Ignore whitespaces
- if b <= 0x20u8 then continue
- if not b.is_base64_char then continue
- curr <<= 6
- curr += b.to_base64_char.to_i
- cnt += 1
- if cnt == 4 then
- result.add(((curr & 0xFF0000) >> 16).to_b)
- result.add(((curr & 0xFF00) >> 8).to_b)
- result.add((curr & 0xFF).to_b)
- curr = 0
- cnt = 0
- end
- end
- if endpos != -1 or cnt != 0 then
- var pads = 0
- for i in [endpos .. length[ do
- var b = self[i]
- if b <= 0x20u8 then continue
- pads += 1
- end
- if cnt == 2 then
- curr >>= 4
- result.add(curr.to_b)
- else if cnt == 3 then
- curr >>= 2
- result.add(((curr & 0xFF00) >> 8).to_b)
- result.add((curr & 0xFF).to_b)
- end
- end
- return result
- end
-
- # Is `self` a well-formed Base64 entity ?
- #
- # ~~~nit
- # assert "Qn03".is_base64
- # assert not "#sd=".is_base64
- # ~~~
- fun is_base64(length: Int): Bool do return check_base64(length) == null
-
- # Is `self` a well-formed Base64 entity ?
- #
- # Will return an Error otherwise with info on which part is erroneous.
- fun check_base64(length: Int): nullable Error do
- var rlen = 0
- var opos = length
- for i in [0 .. length[ do
- if self[i] == b'=' then
- opos = i
- break
- end
- if self[i].is_whitespace then continue
- if not self[i].is_base64_char then return new Error("Invalid Base64 character at position {i}: {self[i].ascii}")
- rlen += 1
- if rlen > 4 then rlen -= 4
- end
- var pad = 0
- for i in [opos .. length[ do
- if self[i].is_whitespace then continue
- if self[i] != b'=' then return new Error("Invalid padding character {self[i].ascii} at position {i}")
- pad += 1
- end
- if rlen + pad != 4 then return new Error("Invalid padding length")
- return null
- 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: Bytes do return items.encode_base64(length)
-
- # Decodes the receiver string to base64 using a custom padding character.
- #
- # Default padding character `=`
- fun decode_base64: Bytes do return items.decode_base64(length)
-
- # Is `self` a well-formed Base64 entity ?
- fun is_base64: Bool do return items.is_base64(length)
-
- # Is `self` a well-formed Base64 entity ?
- #
- # Will return an Error otherwise with info on which part is erroneous.
- fun check_base64: nullable Error do return items.check_base64(length)
-end
-
-redef class Text
-
- # Encodes the receiver string to base64 using a custom padding character.
- #
- # If using the default padding character `=`, see `encode_base64`.
- fun encode_base64: String do return to_cstring.encode_base64(byte_length).to_s
-
- # Decodes the receiver string to base64 using a custom padding character.
- #
- # Default padding character `=`
- fun decode_base64: Bytes do return to_cstring.decode_base64(byte_length)
-
- # Is `self` a well-formed Base64 entity ?
- fun is_base64: Bool do return to_cstring.is_base64(byte_length)
-
- # Is `self` a well-formed Base64 entity ?
- #
- # Will return an Error otherwise with info on which part is erroneous.
- fun check_base64: nullable Error do return to_cstring.check_base64(byte_length)
-end
-
-redef class FlatText
- redef fun encode_base64 do return fast_cstring.encode_base64(byte_length).to_s
-
- redef fun decode_base64 do return fast_cstring.decode_base64(byte_length)
-
- redef fun is_base64 do return fast_cstring.is_base64(byte_length)
-
- redef fun check_base64 do return fast_cstring.check_base64(byte_length)
-end
nitlanguage / nit.git / blobdiff