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phobos/std/base64.d
Walter Bright 1b8314c4e0 add source links
2011-02-26 15:32:21 -06:00

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// Written in the D programming language.
/**
* Encoding / Decoding Base64 format.
*
* Implemented according to $(WEB tools.ietf.org/html/rfc4648,
* RFC 4648 - The Base16, Base32, and Base64 Data Encodings).
*
* Example:
* -----
* ubyte[] data = [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e];
* Base64.encode(data); //-> "FPucA9l+"
* Base64.decode("FPucA9l+"); //-> [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e]
* -----
*
* Support Range interface using Encoder / Decoder.
*
* Example:
* -----
* // Create MIME Base64 with CRLF, per line 76.
* foreach (encoded; Base64.encoder(f.byChunk(57))) {
* mime64.put(encoded);
* mime64.put("\r\n");
* }
* -----
*
* Copyright: Masahiro Nakagawa 2010-.
* License: $(WEB boost.org/LICENSE_1_0.txt, Boost License 1.0).
* Authors: Masahiro Nakagawa, Daniel Murphy (Single value Encoder and Decoder)
* Source: $(PHOBOSSRC std/_base64.d)
*/
module std.base64;
import std.exception; // enforce
import std.range; // isInputRange, isOutputRange, isForwardRange, ElementType, hasLength
import std.traits; // isArray
version(unittest) import std.algorithm, std.conv, std.file, std.stdio;
/**
* The Base64
*/
alias Base64Impl!('+', '/') Base64;
/**
* The "URL and Filename safe" Base64
*/
alias Base64Impl!('-', '_') Base64URL;
/**
* Core implementation for Base64 format.
*
* Example:
* -----
* alias Base64Impl!('+', '/') Base64; // The Base64 format(Already defined).
* alias Base64Impl!('!', '=', Base64.NoPadding) Base64Re; // non-standard Base64 format for Regular expression
* -----
*
* NOTE:
* encoded-string doesn't have padding character if set Padding parameter to NoPadding.
*/
template Base64Impl(char Map62th, char Map63th, char Padding = '=')
{
enum NoPadding = '\0'; /// represents no-padding encoding
// Verify Base64 characters
static assert(Map62th < 'A' || Map62th > 'Z', "Character '" ~ Map62th ~ "' cannot be used twice");
static assert(Map63th < 'A' || Map63th > 'Z', "Character '" ~ Map63th ~ "' cannot be used twice");
static assert(Padding < 'A' || Padding > 'Z', "Character '" ~ Padding ~ "' cannot be used twice");
static assert(Map62th < 'a' || Map62th > 'z', "Character '" ~ Map62th ~ "' cannot be used twice");
static assert(Map63th < 'a' || Map63th > 'z', "Character '" ~ Map63th ~ "' cannot be used twice");
static assert(Padding < 'a' || Padding > 'z', "Character '" ~ Padding ~ "' cannot be used twice");
static assert(Map62th < '0' || Map62th > '9', "Character '" ~ Map62th ~ "' cannot be used twice");
static assert(Map63th < '0' || Map63th > '9', "Character '" ~ Map63th ~ "' cannot be used twice");
static assert(Padding < '0' || Padding > '9', "Character '" ~ Padding ~ "' cannot be used twice");
static assert(Map62th != Map63th, "Character '" ~ Map63th ~ "' cannot be used twice");
static assert(Map62th != Padding, "Character '" ~ Padding ~ "' cannot be used twice");
static assert(Map63th != Padding, "Character '" ~ Padding ~ "' cannot be used twice");
static assert(Map62th != NoPadding, "'\\0' is not a valid Base64character");
static assert(Map63th != NoPadding, "'\\0' is not a valid Base64character");
/* Encode functions */
private immutable EncodeMap = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" ~ Map62th ~ Map63th;
/**
* Calculates the minimum length for encoding.
*
* Params:
* sourceLength = the length of source array.
*
* Returns:
* the calculated length using $(D_PARAM sourceLength).
*/
@safe
pure nothrow size_t encodeLength(in size_t sourceLength)
{
static if (Padding == NoPadding)
return (sourceLength / 3) * 4 + (sourceLength % 3 == 0 ? 0 : sourceLength % 3 == 1 ? 2 : 3);
else
return (sourceLength / 3 + (sourceLength % 3 ? 1 : 0)) * 4;
}
// ubyte[] to char[]
/**
* Encodes $(D_PARAM source) into $(D_PARAM buffer).
*
* Params:
* source = an $(D InputRange) to encode.
* range = a buffer to store encoded result.
*
* Returns:
* the encoded string that slices buffer.
*/
@trusted
pure char[] encode(R1, R2)(in R1 source, R2 buffer) if (isArray!R1 && is(ElementType!R1 : ubyte) &&
is(R2 == char[]))
in
{
assert(buffer.length >= encodeLength(source.length), "Insufficient buffer for encoding");
}
out(result)
{
assert(result.length == encodeLength(source.length), "The length of result is different from Base64");
}
body
{
immutable srcLen = source.length;
if (srcLen == 0)
return [];
immutable blocks = srcLen / 3;
immutable remain = srcLen % 3;
auto bufptr = buffer.ptr;
auto srcptr = source.ptr;
foreach (Unused; 0..blocks) {
immutable val = srcptr[0] << 16 | srcptr[1] << 8 | srcptr[2];
*bufptr++ = EncodeMap[val >> 18 ];
*bufptr++ = EncodeMap[val >> 12 & 0x3f];
*bufptr++ = EncodeMap[val >> 6 & 0x3f];
*bufptr++ = EncodeMap[val & 0x3f];
srcptr += 3;
}
if (remain) {
immutable val = srcptr[0] << 16 | (remain == 2 ? srcptr[1] << 8 : 0);
*bufptr++ = EncodeMap[val >> 18 ];
*bufptr++ = EncodeMap[val >> 12 & 0x3f];
final switch (remain) {
case 2:
*bufptr++ = EncodeMap[val >> 6 & 0x3f];
static if (Padding != NoPadding)
*bufptr++ = Padding;
break;
case 1:
static if (Padding != NoPadding) {
*bufptr++ = Padding;
*bufptr++ = Padding;
}
break;
}
}
// encode method can't assume buffer length. So, slice needed.
return buffer[0..bufptr - buffer.ptr];
}
// InputRange to char[]
/**
* ditto
*/
char[] encode(R1, R2)(R1 source, R2 buffer) if (!isArray!R1 && isInputRange!R1 &&
is(ElementType!R1 : ubyte) && hasLength!R1 &&
is(R2 == char[]))
in
{
assert(buffer.length >= encodeLength(source.length), "Insufficient buffer for encoding");
}
out(result)
{
// @@@BUG@@@ D's DbC can't caputre an argument of function and store the result of precondition.
//assert(result.length == encodeLength(source.length), "The length of result is different from Base64");
}
body
{
immutable srcLen = source.length;
if (srcLen == 0)
return [];
immutable blocks = srcLen / 3;
immutable remain = srcLen % 3;
auto bufptr = buffer.ptr;
foreach (Unused; 0..blocks) {
immutable v1 = source.front; source.popFront();
immutable v2 = source.front; source.popFront();
immutable v3 = source.front; source.popFront();
immutable val = v1 << 16 | v2 << 8 | v3;
*bufptr++ = EncodeMap[val >> 18 ];
*bufptr++ = EncodeMap[val >> 12 & 0x3f];
*bufptr++ = EncodeMap[val >> 6 & 0x3f];
*bufptr++ = EncodeMap[val & 0x3f];
}
if (remain) {
size_t val = source.front << 16;
if (remain == 2) {
source.popFront();
val |= source.front << 8;
}
*bufptr++ = EncodeMap[val >> 18 ];
*bufptr++ = EncodeMap[val >> 12 & 0x3f];
final switch (remain) {
case 2:
*bufptr++ = EncodeMap[val >> 6 & 0x3f];
static if (Padding != NoPadding)
*bufptr++ = Padding;
break;
case 1:
static if (Padding != NoPadding) {
*bufptr++ = Padding;
*bufptr++ = Padding;
}
break;
}
}
// @@@BUG@@@ Workaround for DbC problem. See comment on 'out'.
version (unittest) assert(bufptr - buffer.ptr == encodeLength(srcLen), "The length of result is different from Base64");
// encode method can't assume buffer length. So, slice needed.
return buffer[0..bufptr - buffer.ptr];
}
// ubyte[] to OutputRange
/**
* Encodes $(D_PARAM source) into $(D_PARAM range).
*
* Params:
* source = an $(D InputRange) to encode.
* range = an $(D OutputRange) to put encoded result.
*
* Returns:
* the number of calling put.
*/
size_t encode(R1, R2)(in R1 source, R2 range) if (isArray!R1 && is(ElementType!R1 : ubyte) &&
!is(R2 == char[]))
out(result)
{
assert(result == encodeLength(source.length), "The number of put is different from the length of Base64");
}
body
{
immutable srcLen = source.length;
if (srcLen == 0)
return 0;
immutable blocks = srcLen / 3;
immutable remain = srcLen % 3;
auto srcptr = source.ptr;
size_t pcount;
foreach (Unused; 0..blocks) {
immutable val = srcptr[0] << 16 | srcptr[1] << 8 | srcptr[2];
put(range, EncodeMap[val >> 18 ]);
put(range, EncodeMap[val >> 12 & 0x3f]);
put(range, EncodeMap[val >> 6 & 0x3f]);
put(range, EncodeMap[val & 0x3f]);
srcptr += 3;
pcount += 4;
}
if (remain) {
immutable val = srcptr[0] << 16 | (remain == 2 ? srcptr[1] << 8 : 0);
put(range, EncodeMap[val >> 18 ]);
put(range, EncodeMap[val >> 12 & 0x3f]);
pcount += 2;
final switch (remain) {
case 2:
put(range, EncodeMap[val >> 6 & 0x3f]);
pcount++;
static if (Padding != NoPadding) {
put(range, Padding);
pcount++;
}
break;
case 1:
static if (Padding != NoPadding) {
put(range, Padding);
put(range, Padding);
pcount += 2;
}
break;
}
}
return pcount;
}
// InputRange to OutputRange
/**
* ditto
*/
size_t encode(R1, R2)(R1 source, R2 range) if (!isArray!R1 && isInputRange!R1 &&
is(ElementType!R1 : ubyte) && hasLength!R1 &&
!is(R2 == char[]) && isOutputRange!(R2, char))
out(result)
{
// @@@BUG@@@ Workaround for DbC problem.
//assert(result == encodeLength(source.length), "The number of put is different from the length of Base64");
}
body
{
immutable srcLen = source.length;
if (srcLen == 0)
return 0;
immutable blocks = srcLen / 3;
immutable remain = srcLen % 3;
size_t pcount;
foreach (Unused; 0..blocks) {
immutable v1 = source.front; source.popFront();
immutable v2 = source.front; source.popFront();
immutable v3 = source.front; source.popFront();
immutable val = v1 << 16 | v2 << 8 | v3;
put(range, EncodeMap[val >> 18 ]);
put(range, EncodeMap[val >> 12 & 0x3f]);
put(range, EncodeMap[val >> 6 & 0x3f]);
put(range, EncodeMap[val & 0x3f]);
pcount += 4;
}
if (remain) {
size_t val = source.front << 16;
if (remain == 2) {
source.popFront();
val |= source.front << 8;
}
put(range, EncodeMap[val >> 18 ]);
put(range, EncodeMap[val >> 12 & 0x3f]);
pcount += 2;
final switch (remain) {
case 2:
put(range, EncodeMap[val >> 6 & 0x3f]);
pcount++;
static if (Padding != NoPadding) {
put(range, Padding);
pcount++;
}
break;
case 1:
static if (Padding != NoPadding) {
put(range, Padding);
put(range, Padding);
pcount += 2;
}
break;
}
}
// @@@BUG@@@ Workaround for DbC problem.
version (unittest) assert(pcount == encodeLength(srcLen), "The number of put is different from the length of Base64");
return pcount;
}
/**
* Encodes $(D_PARAM source) to new buffer.
*
* Shortcut to encode(source, buffer) function.
*/
@safe
pure char[] encode(Range)(Range source) if (isArray!Range && is(ElementType!Range : ubyte))
{
return encode(source, new char[encodeLength(source.length)]);
}
/**
* ditto
*/
char[] encode(Range)(Range source) if (!isArray!Range && isInputRange!Range &&
is(ElementType!Range : ubyte) && hasLength!Range)
{
return encode(source, new char[encodeLength(source.length)]);
}
/**
* Range that encodes chunk data at a time.
*/
struct Encoder(Range) if (isInputRange!Range && (is(ElementType!Range : const(ubyte)[]) ||
is(ElementType!Range : const(char)[])))
{
private:
Range range_;
char[] buffer_, encoded_;
public:
this(Range range)
{
range_ = range;
doEncoding();
}
/**
* Range primitive operation that checks iteration state.
*
* Returns:
* true if there are no more elements to be iterated.
*/
@property @trusted
bool empty() const
{
return range_.empty;
}
/**
* Range primitive operation that returns the currently iterated element.
*
* Returns:
* the encoded string.
*/
@property @safe
nothrow char[] front()
{
return encoded_;
}
/**
* Range primitive operation that advances the range to its next element.
*
* Throws:
* an Exception when you try to call popFront on empty range.
*/
void popFront()
{
enforce(!empty, "Cannot call popFront on Encoder with no data remaining");
range_.popFront();
/*
* This check is very ugly. I think this is a Range's flaw.
* I very strongly want the Range guideline for unified implementation.
*
* In this case, Encoder becomes a beautiful implementation if 'front' performs Base64 encoding.
*/
if (!empty)
doEncoding();
}
static if (isForwardRange!Range) {
/**
* Captures a Range state.
*
* Returns:
* a copy of $(D this).
*/
@property
typeof(this) save()
{
typeof(return) encoder;
encoder.range_ = range_.save;
encoder.buffer_ = buffer_.dup;
encoder.encoded_ = encoder.buffer_[0..encoded_.length];
return encoder;
}
}
private:
void doEncoding()
{
auto data = cast(const(ubyte)[])range_.front;
auto size = encodeLength(data.length);
if (size > buffer_.length)
buffer_.length = size;
encoded_ = encode(data, buffer_);
}
}
/**
* Range that encodes single character at a time.
*/
struct Encoder(Range) if (isInputRange!Range && is(ElementType!Range : ubyte))
{
private:
Range range_;
ubyte first;
int pos, padding;
public:
this(Range range)
{
range_ = range;
static if (isForwardRange!Range)
range_ = range_.save;
if (range_.empty)
pos = -1;
else
popFront();
}
/**
* Range primitive operation that checks iteration state.
*
* Returns:
* true if there are no more elements to be iterated.
*/
@property @safe
nothrow bool empty() const
{
static if (Padding == NoPadding)
return pos < 0;
else
return pos < 0 && !padding;
}
/**
* Range primitive operation that returns the currently iterated element.
*
* Returns:
* the encoded character.
*/
@property @safe
nothrow ubyte front()
{
return first;
}
/**
* Range primitive operation that advances the range to its next element.
*
* Throws:
* an Exception when you try to call popFront on empty range.
*/
void popFront()
{
enforce(!empty, "Cannot call popFront on Encoder with no data remaining");
static if (Padding != NoPadding)
if (padding) {
first = Padding;
pos = -1;
padding--;
return;
}
if (range_.empty) {
pos = -1;
return;
}
final switch (pos) {
case 0:
first = EncodeMap[range_.front >> 2];
break;
case 1:
immutable t = (range_.front & 0b11) << 4;
range_.popFront();
if (range_.empty) {
first = EncodeMap[t];
padding = 3;
} else {
first = EncodeMap[t | (range_.front >> 4)];
}
break;
case 2:
immutable t = (range_.front & 0b1111) << 2;
range_.popFront();
if (range_.empty) {
first = EncodeMap[t];
padding = 2;
} else {
first = EncodeMap[t | (range_.front >> 6)];
}
break;
case 3:
first = EncodeMap[range_.front & 0b111111];
range_.popFront();
break;
}
++pos %= 4;
}
static if (isForwardRange!Range) {
/**
* Captures a Range state.
*
* Returns:
* a copy of $(D this).
*/
@property
typeof(this) save()
{
auto encoder = this;
encoder.range_ = encoder.range_.save;
return encoder;
}
}
}
/**
* Iterates through an $(D InputRange) at a time by using $(D Encoder).
*
* Default $(D Encoder) encodes chunk data.
*
* Example:
* -----
* foreach (encoded; Base64.encoder(f.byLine())) {
* ... use encoded line ...
* }
* -----
*
* In addition, You can use $(D Encoder) that returns encoded single character.
* This $(D Encoder) performs Range-based and lazy encoding.
*
* Example:
* -----
* // The ElementType of data is not aggregation type
* foreach (encoded; Base64.encoder(data)) {
* ... use encoded character ...
* }
* -----
*
* Params:
* range = an $(D InputRange) to iterate.
*
* Returns:
* a $(D Encoder) object instantiated and initialized according to the arguments.
*/
Encoder!(Range) encoder(Range)(Range range) if (isInputRange!Range)
{
return typeof(return)(range);
}
/* Decode functions */
private immutable int[char.max + 1] DecodeMap = [
'A':0b000000, 'B':0b000001, 'C':0b000010, 'D':0b000011, 'E':0b000100,
'F':0b000101, 'G':0b000110, 'H':0b000111, 'I':0b001000, 'J':0b001001,
'K':0b001010, 'L':0b001011, 'M':0b001100, 'N':0b001101, 'O':0b001110,
'P':0b001111, 'Q':0b010000, 'R':0b010001, 'S':0b010010, 'T':0b010011,
'U':0b010100, 'V':0b010101, 'W':0b010110, 'X':0b010111, 'Y':0b011000,
'Z':0b011001, 'a':0b011010, 'b':0b011011, 'c':0b011100, 'd':0b011101,
'e':0b011110, 'f':0b011111, 'g':0b100000, 'h':0b100001, 'i':0b100010,
'j':0b100011, 'k':0b100100, 'l':0b100101, 'm':0b100110, 'n':0b100111,
'o':0b101000, 'p':0b101001, 'q':0b101010, 'r':0b101011, 's':0b101100,
't':0b101101, 'u':0b101110, 'v':0b101111, 'w':0b110000, 'x':0b110001,
'y':0b110010, 'z':0b110011, '0':0b110100, '1':0b110101, '2':0b110110,
'3':0b110111, '4':0b111000, '5':0b111001, '6':0b111010, '7':0b111011,
'8':0b111100, '9':0b111101, Map62th:0b111110, Map63th:0b111111, Padding:-1
];
/**
* Calculates the minimum length for decoding.
*
* Params:
* sourceLength = the length of source array.
*
* Returns:
* calculated length using $(D_PARAM sourceLength).
*/
@safe
pure nothrow size_t decodeLength(in size_t sourceLength)
in
{
static if (Padding == NoPadding)
assert(sourceLength % 4 != 1, "Invalid no-padding Base64 format");
else
assert(sourceLength % 4 == 0, "Invalid Base64 format");
}
body
{
static if (Padding == NoPadding)
return (sourceLength / 4) * 3 + (sourceLength % 4 == 0 ? 0 : sourceLength % 4 == 2 ? 1 : 2);
else
return (sourceLength / 4) * 3;
}
// char[] to ubyte[]
/**
* Decodes $(D_PARAM source) into $(D_PARAM buffer).
*
* Params:
* source = an $(D InputRange) to decode.
* buffer = a buffer to store decoded result.
*
* Returns:
* the decoded string that slices buffer.
*
* Throws:
* an Exception if $(D_PARAM source) has character outside base-alphabet.
*/
@trusted
pure ubyte[] decode(R1, R2)(in R1 source, R2 buffer) if (isArray!R1 && is(ElementType!R1 : dchar) &&
is(R2 == ubyte[]) && isOutputRange!(R2, ubyte))
in
{
assert(buffer.length >= decodeLength(source.length), "Insufficient buffer for decoding");
}
out(result)
{
immutable expect = decodeLength(source.length) - (source.length == 0 ? 0 :
source[$ - 2] == Padding ? 2 :
source[$ - 1] == Padding ? 1 : 0);
assert(result.length == expect, "The length of result is different from the expected length");
}
body
{
immutable srcLen = source.length;
if (srcLen == 0)
return [];
immutable blocks = srcLen / 4;
auto srcptr = source.ptr;
auto bufptr = buffer.ptr;
foreach (Unused; 0..blocks) {
immutable v1 = decodeChar(*srcptr++);
immutable v2 = decodeChar(*srcptr++);
*bufptr++ = cast(ubyte)(v1 << 2 | v2 >> 4);
immutable v3 = decodeChar(*srcptr++);
if (v3 == -1)
break;
*bufptr++ = cast(ubyte)((v2 << 4 | v3 >> 2) & 0xff);
immutable v4 = decodeChar(*srcptr++);
if (v4 == -1)
break;
*bufptr++ = cast(ubyte)((v3 << 6 | v4) & 0xff);
}
static if (Padding == NoPadding) {
immutable remain = srcLen % 4;
if (remain) {
immutable v1 = decodeChar(*srcptr++);
immutable v2 = decodeChar(*srcptr++);
*bufptr++ = cast(ubyte)(v1 << 2 | v2 >> 4);
if (remain == 3)
*bufptr++ = cast(ubyte)((v2 << 4 | decodeChar(*srcptr++) >> 2) & 0xff);
}
}
return buffer[0..bufptr - buffer.ptr];
}
// InputRange to ubyte[]
/**
* ditto
*/
ubyte[] decode(R1, R2)(R1 source, R2 buffer) if (!isArray!R1 && isInputRange!R1 &&
is(ElementType!R1 : dchar) && hasLength!R1 &&
is(R2 == ubyte[]) && isOutputRange!(R2, ubyte))
in
{
assert(buffer.length >= decodeLength(source.length), "Insufficient buffer for decoding");
}
out(result)
{
// @@@BUG@@@ Workaround for DbC problem.
//immutable expect = decodeLength(source.length) - 2;
//assert(result.length >= expect, "The length of result is smaller than expected length");
}
body
{
immutable srcLen = source.length;
if (srcLen == 0)
return [];
immutable blocks = srcLen / 4;
auto bufptr = buffer.ptr;
foreach (Unused; 0..blocks) {
immutable v1 = decodeChar(source.front); source.popFront();
immutable v2 = decodeChar(source.front); source.popFront();
*bufptr++ = cast(ubyte)(v1 << 2 | v2 >> 4);
immutable v3 = decodeChar(source.front);
if (v3 == -1)
break;
*bufptr++ = cast(ubyte)((v2 << 4 | v3 >> 2) & 0xff);
source.popFront();
immutable v4 = decodeChar(source.front);
if (v4 == -1)
break;
*bufptr++ = cast(ubyte)((v3 << 6 | v4) & 0xff);
source.popFront();
}
static if (Padding == NoPadding) {
immutable remain = srcLen % 4;
if (remain) {
immutable v1 = decodeChar(source.front); source.popFront();
immutable v2 = decodeChar(source.front);
*bufptr++ = cast(ubyte)(v1 << 2 | v2 >> 4);
if (remain == 3) {
source.popFront();
*bufptr++ = cast(ubyte)((v2 << 4 | decodeChar(source.front) >> 2) & 0xff);
}
}
}
// @@@BUG@@@ Workaround for DbC problem.
version (unittest) assert((bufptr - buffer.ptr) >= (decodeLength(srcLen) - 2), "The length of result is smaller than expected length");
return buffer[0..bufptr - buffer.ptr];
}
// char[] to OutputRange
/**
* Decodes $(D_PARAM source) into $(D_PARAM range).
*
* Params:
* source = an $(D InputRange) to decode.
* range = an $(D OutputRange) to put decoded result
*
* Returns:
* the number of calling put.
*
* Throws:
* an Exception if $(D_PARAM source) has character outside base-alphabet.
*/
size_t decode(R1, R2)(in R1 source, R2 range) if (isArray!R1 && is(ElementType!R1 : dchar) &&
!is(R2 == ubyte[]) && isOutputRange!(R2, ubyte))
out(result)
{
immutable expect = decodeLength(source.length) - (source.length == 0 ? 0 :
source[$ - 2] == Padding ? 2 :
source[$ - 1] == Padding ? 1 : 0);
assert(result == expect, "The result of decode is different from the expected");
}
body
{
immutable srcLen = source.length;
if (srcLen == 0)
return 0;
immutable blocks = srcLen / 4;
auto srcptr = source.ptr;
size_t pcount;
foreach (Unused; 0..blocks) {
immutable v1 = decodeChar(*srcptr++);
immutable v2 = decodeChar(*srcptr++);
put(range, cast(ubyte)(v1 << 2 | v2 >> 4));
pcount++;
immutable v3 = decodeChar(*srcptr++);
if (v3 == -1)
break;
put(range, cast(ubyte)((v2 << 4 | v3 >> 2) & 0xff));
pcount++;
immutable v4 = decodeChar(*srcptr++);
if (v4 == -1)
break;
put(range, cast(ubyte)((v3 << 6 | v4) & 0xff));
pcount++;
}
static if (Padding == NoPadding) {
immutable remain = srcLen % 4;
if (remain) {
immutable v1 = decodeChar(*srcptr++);
immutable v2 = decodeChar(*srcptr++);
put(range, cast(ubyte)(v1 << 2 | v2 >> 4));
pcount++;
if (remain == 3) {
put(range, cast(ubyte)((v2 << 4 | decodeChar(*srcptr++) >> 2) & 0xff));
pcount++;
}
}
}
return pcount;
}
// InputRange to OutputRange
/**
* ditto
*/
size_t decode(R1, R2)(R1 source, R2 range) if (!isArray!R1 && isInputRange!R1 &&
is(ElementType!R1 : dchar) && hasLength!R1 &&
!is(R2 == ubyte[]) && isOutputRange!(R2, ubyte))
out(result)
{
// @@@BUG@@@ Workaround for DbC problem.
//immutable expect = decodeLength(source.length) - 2;
//assert(result >= expect, "The length of result is smaller than expected length");
}
body
{
immutable srcLen = source.length;
if (srcLen == 0)
return 0;
immutable blocks = srcLen / 4;
size_t pcount;
foreach (Unused; 0..blocks) {
immutable v1 = decodeChar(source.front); source.popFront();
immutable v2 = decodeChar(source.front); source.popFront();
put(range, cast(ubyte)(v1 << 2 | v2 >> 4));
pcount++;
immutable v3 = decodeChar(source.front);
if (v3 == -1)
break;
put(range, cast(ubyte)((v2 << 4 | v3 >> 2) & 0xff));
source.popFront();
pcount++;
immutable v4 = decodeChar(source.front);
if (v4 == -1)
break;
put(range, cast(ubyte)((v3 << 6 | v4) & 0xff));
source.popFront();
pcount++;
}
static if (Padding == NoPadding) {
immutable remain = srcLen % 4;
if (remain) {
immutable v1 = decodeChar(source.front); source.popFront();
immutable v2 = decodeChar(source.front);
put(range, cast(ubyte)(v1 << 2 | v2 >> 4));
pcount++;
if (remain == 3) {
source.popFront();
put(range, cast(ubyte)((v2 << 4 | decodeChar(source.front) >> 2) & 0xff));
pcount++;
}
}
}
// @@@BUG@@@ Workaround for DbC problem.
version (unittest) assert(pcount >= (decodeLength(srcLen) - 2), "The length of result is smaller than expected length");
return pcount;
}
/**
* Decodes $(D_PARAM source) into new buffer.
*
* Shortcut to decode(source, buffer) function.
*/
@safe
pure ubyte[] decode(Range)(Range source) if (isArray!Range && is(ElementType!Range : dchar))
{
return decode(source, new ubyte[decodeLength(source.length)]);
}
/**
* ditto
*/
ubyte[] decode(Range)(Range source) if (!isArray!Range && isInputRange!Range &&
is(ElementType!Range : dchar) && hasLength!Range)
{
return decode(source, new ubyte[decodeLength(source.length)]);
}
/**
* Range that decodes chunk data at a time.
*/
struct Decoder(Range) if (isInputRange!Range && (is(ElementType!Range : const(char)[]) ||
is(ElementType!Range : const(ubyte)[])))
{
private:
Range range_;
ubyte[] buffer_, decoded_;
public:
this(Range range)
{
range_ = range;
doDecoding();
}
/**
* Range primitive operation that checks iteration state.
*
* Returns:
* true if there are no more elements to be iterated.
*/
@property @trusted
bool empty() const
{
return range_.empty;
}
/**
* Range primitive operation that returns the currently iterated element.
*
* Returns:
* the decoded result.
*/
@property @safe
nothrow ubyte[] front()
{
return decoded_;
}
/**
* Range primitive operation that advances the range to its next element.
*
* Throws:
* an Exception when you try to call popFront on empty range.
*/
void popFront()
{
enforce(!empty, "Cannot call popFront on Decoder with no data remaining.");
range_.popFront();
/*
* I mentioned Encoder's popFront.
*/
if (!empty)
doDecoding();
}
static if (isForwardRange!Range) {
/**
* Captures a Range state.
*
* Returns:
* a copy of $(D this).
*/
@property
typeof(this) save()
{
typeof(return) decoder;
decoder.range_ = range_.save;
decoder.buffer_ = buffer_.dup;
decoder.decoded_ = decoder.buffer_[0..decoded_.length];
return decoder;
}
}
private:
void doDecoding()
{
auto data = cast(const(char)[])range_.front;
static if (Padding == NoPadding) {
while (data.length % 4 == 1) {
range_.popFront();
data ~= cast(const(char)[])range_.front;
}
} else {
while (data.length % 4 != 0) {
range_.popFront();
data ~= cast(const(char)[])range_.front;
}
}
auto size = decodeLength(data.length);
if (size > buffer_.length)
buffer_.length = size;
decoded_ = decode(data, buffer_);
}
}
/**
* Range that decodes single character at a time.
*/
struct Decoder(Range) if (isInputRange!Range && is(ElementType!Range : char))
{
private:
Range range_;
ubyte first;
int pos;
public:
this(Range range)
{
range_ = range;
static if (isForwardRange!Range)
range_ = range_.save;
static if (Padding != NoPadding && hasLength!Range)
enforce(range_.length % 4 == 0);
if (range_.empty)
pos = -1;
else
popFront();
}
/**
* Range primitive operation that checks iteration state.
*
* Returns:
* true if there are no more elements to be iterated.
*/
@property @safe
nothrow bool empty() const
{
return pos < 0;
}
/**
* Range primitive operation that returns the currently iterated element.
*
* Returns:
* the decoded result.
*/
@property @safe
nothrow ubyte front()
{
return first;
}
/**
* Range primitive operation that advances the range to its next element.
*
* Throws:
* an Exception when you try to call popFront on empty range.
*/
void popFront()
{
enforce(!empty, "Cannot call popFront on Decoder with no data remaining");
static if (Padding == NoPadding) {
bool endCondition()
{
return range_.empty;
}
} else {
bool endCondition()
{
enforce(!range_.empty, "Missing padding");
return range_.front == Padding;
}
}
if (range_.empty || range_.front == Padding) {
pos = -1;
return;
}
final switch (pos) {
case 0:
enforce(!endCondition(), "Premature end of data found");
immutable t = DecodeMap[range_.front] << 2;
range_.popFront();
enforce(!endCondition(), "Premature end of data found");
first = cast(ubyte)(t | (DecodeMap[range_.front] >> 4));
break;
case 1:
immutable t = (DecodeMap[range_.front] & 0b1111) << 4;
range_.popFront();
if (endCondition()) {
pos = -1;
return;
} else {
first = cast(ubyte)(t | (DecodeMap[range_.front] >> 2));
}
break;
case 2:
immutable t = (DecodeMap[range_.front] & 0b11) << 6;
range_.popFront();
if (endCondition()) {
pos = -1;
return;
} else {
first = cast(ubyte)(t | DecodeMap[range_.front]);
}
range_.popFront();
break;
}
++pos %= 3;
}
static if (isForwardRange!Range) {
/**
* Captures a Range state.
*
* Returns:
* a copy of $(D this).
*/
@property
typeof(this) save()
{
auto decoder = this;
decoder.range_ = decoder.range_.save;
return decoder;
}
}
}
/**
* Iterates through an $(D InputRange) at a time by using $(D Decoder).
*
* Default $(D Decoder) decodes chunk data.
*
* Example:
* -----
* foreach (decoded; Base64.decoder(f.byLine())) {
* ... use decoded line ...
* }
* -----
*
* In addition, You can use $(D Decoder) that returns decoded single character.
* This $(D Decoder) performs Range-based and lazy decoding.
*
* Example:
* -----
* auto encoded = Base64.encoder(cast(ubyte[])"0123456789");
* foreach (n; map!q{a - '0'}(Base64.decoder(encoded))) {
* ... do something with n ...
* }
* -----
*
* NOTE:
* If you use $(D ByChunk), chunk-size should be the multiple of 4.
* $(D Decoder) can't judge a encode-boundary.
*
* Params:
* range = an $(D InputRange) to iterate.
*
* Returns:
* a $(D Decoder) object instantiated and initialized according to the arguments.
*/
Decoder!(Range) decoder(Range)(Range range) if (isInputRange!Range)
{
return typeof(return)(range);
}
private:
@safe
pure int decodeChar()(char chr)
{
immutable val = DecodeMap[chr];
// enforce can't be a pure function, so I use trivial check.
if (val == 0 && chr != 'A')
throw new Exception("Invalid character: " ~ chr);
return val;
}
@safe
pure int decodeChar()(dchar chr)
{
// See above comment.
if (chr > 0x7f)
throw new Exception("Base64-encoded character must be a single byte");
return decodeChar(cast(char)chr);
}
}
unittest
{
alias Base64Impl!('!', '=', Base64.NoPadding) Base64Re;
// Test vectors from RPC 4648
ubyte[][string] tv = [
"" :cast(ubyte[])"",
"f" :cast(ubyte[])"f",
"fo" :cast(ubyte[])"fo",
"foo" :cast(ubyte[])"foo",
"foob" :cast(ubyte[])"foob",
"fooba" :cast(ubyte[])"fooba",
"foobar":cast(ubyte[])"foobar"
];
{ // Base64
// encode
assert(Base64.encodeLength(tv[""].length) == 0);
assert(Base64.encodeLength(tv["f"].length) == 4);
assert(Base64.encodeLength(tv["fo"].length) == 4);
assert(Base64.encodeLength(tv["foo"].length) == 4);
assert(Base64.encodeLength(tv["foob"].length) == 8);
assert(Base64.encodeLength(tv["fooba"].length) == 8);
assert(Base64.encodeLength(tv["foobar"].length) == 8);
assert(Base64.encode(tv[""]) == "");
assert(Base64.encode(tv["f"]) == "Zg==");
assert(Base64.encode(tv["fo"]) == "Zm8=");
assert(Base64.encode(tv["foo"]) == "Zm9v");
assert(Base64.encode(tv["foob"]) == "Zm9vYg==");
assert(Base64.encode(tv["fooba"]) == "Zm9vYmE=");
assert(Base64.encode(tv["foobar"]) == "Zm9vYmFy");
// decode
assert(Base64.decodeLength(Base64.encode(tv[""]).length) == 0);
assert(Base64.decodeLength(Base64.encode(tv["f"]).length) == 3);
assert(Base64.decodeLength(Base64.encode(tv["fo"]).length) == 3);
assert(Base64.decodeLength(Base64.encode(tv["foo"]).length) == 3);
assert(Base64.decodeLength(Base64.encode(tv["foob"]).length) == 6);
assert(Base64.decodeLength(Base64.encode(tv["fooba"]).length) == 6);
assert(Base64.decodeLength(Base64.encode(tv["foobar"]).length) == 6);
assert(Base64.decode(Base64.encode(tv[""])) == tv[""]);
assert(Base64.decode(Base64.encode(tv["f"])) == tv["f"]);
assert(Base64.decode(Base64.encode(tv["fo"])) == tv["fo"]);
assert(Base64.decode(Base64.encode(tv["foo"])) == tv["foo"]);
assert(Base64.decode(Base64.encode(tv["foob"])) == tv["foob"]);
assert(Base64.decode(Base64.encode(tv["fooba"])) == tv["fooba"]);
assert(Base64.decode(Base64.encode(tv["foobar"])) == tv["foobar"]);
try {
Base64.decode("ab|c");
assert(false);
} catch (Exception e) {}
}
{ // No padding
// encode
assert(Base64Re.encodeLength(tv[""].length) == 0);
assert(Base64Re.encodeLength(tv["f"].length) == 2);
assert(Base64Re.encodeLength(tv["fo"].length) == 3);
assert(Base64Re.encodeLength(tv["foo"].length) == 4);
assert(Base64Re.encodeLength(tv["foob"].length) == 6);
assert(Base64Re.encodeLength(tv["fooba"].length) == 7);
assert(Base64Re.encodeLength(tv["foobar"].length) == 8);
assert(Base64Re.encode(tv[""]) == "");
assert(Base64Re.encode(tv["f"]) == "Zg");
assert(Base64Re.encode(tv["fo"]) == "Zm8");
assert(Base64Re.encode(tv["foo"]) == "Zm9v");
assert(Base64Re.encode(tv["foob"]) == "Zm9vYg");
assert(Base64Re.encode(tv["fooba"]) == "Zm9vYmE");
assert(Base64Re.encode(tv["foobar"]) == "Zm9vYmFy");
// decode
assert(Base64Re.decodeLength(Base64Re.encode(tv[""]).length) == 0);
assert(Base64Re.decodeLength(Base64Re.encode(tv["f"]).length) == 1);
assert(Base64Re.decodeLength(Base64Re.encode(tv["fo"]).length) == 2);
assert(Base64Re.decodeLength(Base64Re.encode(tv["foo"]).length) == 3);
assert(Base64Re.decodeLength(Base64Re.encode(tv["foob"]).length) == 4);
assert(Base64Re.decodeLength(Base64Re.encode(tv["fooba"]).length) == 5);
assert(Base64Re.decodeLength(Base64Re.encode(tv["foobar"]).length) == 6);
assert(Base64Re.decode(Base64Re.encode(tv[""])) == tv[""]);
assert(Base64Re.decode(Base64Re.encode(tv["f"])) == tv["f"]);
assert(Base64Re.decode(Base64Re.encode(tv["fo"])) == tv["fo"]);
assert(Base64Re.decode(Base64Re.encode(tv["foo"])) == tv["foo"]);
assert(Base64Re.decode(Base64Re.encode(tv["foob"])) == tv["foob"]);
assert(Base64Re.decode(Base64Re.encode(tv["fooba"])) == tv["fooba"]);
assert(Base64Re.decode(Base64Re.encode(tv["foobar"])) == tv["foobar"]);
}
{ // with OutputRange
auto a = Appender!(char[])([]);
auto b = Appender!(ubyte[])([]);
assert(Base64.encode(tv[""], a) == 0);
assert(Base64.decode(a.data, b) == 0);
assert(tv[""] == b.data); a.clear(); b.clear();
assert(Base64.encode(tv["f"], a) == 4);
assert(Base64.decode(a.data, b) == 1);
assert(tv["f"] == b.data); a.clear(); b.clear();
assert(Base64.encode(tv["fo"], a) == 4);
assert(Base64.decode(a.data, b) == 2);
assert(tv["fo"] == b.data); a.clear(); b.clear();
assert(Base64.encode(tv["foo"], a) == 4);
assert(Base64.decode(a.data, b) == 3);
assert(tv["foo"] == b.data); a.clear(); b.clear();
assert(Base64.encode(tv["foob"], a) == 8);
assert(Base64.decode(a.data, b) == 4);
assert(tv["foob"] == b.data); a.clear(); b.clear();
assert(Base64.encode(tv["fooba"], a) == 8);
assert(Base64.decode(a.data, b) == 5);
assert(tv["fooba"] == b.data); a.clear(); b.clear();
assert(Base64.encode(tv["foobar"], a) == 8);
assert(Base64.decode(a.data, b) == 6);
assert(tv["foobar"] == b.data); a.clear(); b.clear();
}
{ // with InputRange
// InputRange to ubyte[] or char[]
auto encoded = Base64.encode(map!(to!(ubyte))(["20", "251", "156", "3", "217", "126"]));
assert(encoded == "FPucA9l+");
assert(Base64.decode(map!q{a}(encoded)) == [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e]);
// InputRange to OutputRange
auto a = Appender!(char[])([]);
auto b = Appender!(ubyte[])([]);
assert(Base64.encode(map!(to!(ubyte))(["20", "251", "156", "3", "217", "126"]), a) == 8);
assert(a.data == "FPucA9l+");
assert(Base64.decode(map!q{a}(a.data), b) == 6);
assert(b.data == [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e]);
}
{ // Encoder and Decoder
{
std.file.write("testingEncoder", "\nf\nfo\nfoo\nfoob\nfooba\nfoobar");
auto witness = ["", "Zg==", "Zm8=", "Zm9v", "Zm9vYg==", "Zm9vYmE=", "Zm9vYmFy"];
auto f = File("testingEncoder");
scope(exit)
{
f.close;
assert(!f.isOpen);
std.file.remove("testingEncoder");
}
size_t i;
foreach (encoded; Base64.encoder(f.byLine()))
assert(encoded == witness[i++]);
assert(i == witness.length);
}
{
std.file.write("testingDecoder", "\nZg==\nZm8=\nZm9v\nZm9vYg==\nZm9vYmE=\nZm9vYmFy");
auto witness = tv.keys.sort;
auto f = File("testingDecoder");
scope(exit)
{
f.close;
assert(!f.isOpen);
std.file.remove("testingDecoder");
}
size_t i;
foreach (decoded; Base64.decoder(f.byLine()))
assert(decoded == witness[i++]);
assert(i == witness.length);
}
{ // ForwardRange
{
auto encoder = Base64.encoder(tv.values.sort);
auto witness = ["", "Zg==", "Zm8=", "Zm9v", "Zm9vYg==", "Zm9vYmE=", "Zm9vYmFy"];
size_t i;
assert(encoder.front == witness[i++]); encoder.popFront();
assert(encoder.front == witness[i++]); encoder.popFront();
assert(encoder.front == witness[i++]); encoder.popFront();
foreach (encoded; encoder.save)
assert(encoded == witness[i++]);
}
{
auto decoder = Base64.decoder(["", "Zg==", "Zm8=", "Zm9v", "Zm9vYg==", "Zm9vYmE=", "Zm9vYmFy"]);
auto witness = tv.values.sort;
size_t i;
assert(decoder.front == witness[i++]); decoder.popFront();
assert(decoder.front == witness[i++]); decoder.popFront();
assert(decoder.front == witness[i++]); decoder.popFront();
foreach (decoded; decoder.save)
assert(decoded == witness[i++]);
}
}
}
{ // Encoder and Decoder for single character encoding and decoding
alias Base64Impl!('+', '/', Base64.NoPadding) Base64NoPadding;
auto tests = [
"" : ["", "", "", ""],
"f" : ["Zg==", "Zg==", "Zg", "Zg"],
"fo" : ["Zm8=", "Zm8=", "Zm8", "Zm8"],
"foo" : ["Zm9v", "Zm9v", "Zm9v", "Zm9v"],
"foob" : ["Zm9vYg==", "Zm9vYg==", "Zm9vYg", "Zm9vYg"],
"fooba" : ["Zm9vYmE=", "Zm9vYmE=", "Zm9vYmE", "Zm9vYmE"],
"foobar" : ["Zm9vYmFy", "Zm9vYmFy", "Zm9vYmFy", "Zm9vYmFy"],
];
foreach (u, e; tests) {
assert(equal(Base64.encoder(cast(ubyte[])u), e[0]));
assert(equal(Base64.decoder(Base64.encoder(cast(ubyte[])u)), u));
assert(equal(Base64URL.encoder(cast(ubyte[])u), e[1]));
assert(equal(Base64URL.decoder(Base64URL.encoder(cast(ubyte[])u)), u));
assert(equal(Base64NoPadding.encoder(cast(ubyte[])u), e[2]));
assert(equal(Base64NoPadding.decoder(Base64NoPadding.encoder(cast(ubyte[])u)), u));
assert(equal(Base64Re.encoder(cast(ubyte[])u), e[3]));
assert(equal(Base64Re.decoder(Base64Re.encoder(cast(ubyte[])u)), u));
}
}
}
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