diff options
Diffstat (limited to 'lib/pure/base64.nim')
| -rw-r--r-- | lib/pure/base64.nim | 151 |
1 files changed, 73 insertions, 78 deletions
diff --git a/lib/pure/base64.nim b/lib/pure/base64.nim index bf196b54d..591d22cc0 100644 --- a/lib/pure/base64.nim +++ b/lib/pure/base64.nim @@ -16,50 +16,48 @@ ## Each Base64 digit represents exactly 6 bits of data. Three 8-bit ## bytes (i.e., a total of 24 bits) can therefore be represented by ## four 6-bit Base64 digits. -## -## Basic usage -## =========== -## + +##[ +# Basic usage ## Encoding data -## ------------- -## -## .. code-block::nim -## import std/base64 -## let encoded = encode("Hello World") -## assert encoded == "SGVsbG8gV29ybGQ=" +]## + +runnableExamples: + let encoded = encode("Hello World") + assert encoded == "SGVsbG8gV29ybGQ=" + ## ## Apart from strings you can also encode lists of integers or characters: ## -## .. code-block::nim -## import std/base64 -## let encodedInts = encode([1,2,3]) -## assert encodedInts == "AQID" -## let encodedChars = encode(['h','e','y']) -## assert encodedChars == "aGV5" -## -## + +runnableExamples: + let encodedInts = encode([1'u8,2,3]) + assert encodedInts == "AQID" + let encodedChars = encode(['h','e','y']) + assert encodedChars == "aGV5" + +##[ ## Decoding data -## ------------- -## -## .. code-block::nim -## import std/base64 -## let decoded = decode("SGVsbG8gV29ybGQ=") -## assert decoded == "Hello World" -## +]## + +runnableExamples: + let decoded = decode("SGVsbG8gV29ybGQ=") + assert decoded == "Hello World" + +##[ ## URL Safe Base64 -## --------------- -## -## .. code-block::nim -## import std/base64 -## doAssert encode("c\xf7>", safe = true) == "Y_c-" -## doAssert encode("c\xf7>", safe = false) == "Y/c+" -## +]## + +runnableExamples: + assert encode("c\xf7>", safe = true) == "Y_c-" + assert encode("c\xf7>", safe = false) == "Y/c+" + ## See also ## ======== ## ## * `hashes module<hashes.html>`_ for efficient computations of hash values for diverse Nim types -## * `md5 module<md5.html>`_ implements the MD5 checksum algorithm -## * `sha1 module<sha1.html>`_ implements a sha1 encoder and decoder +## * `md5 module<md5.html>`_ for the MD5 checksum algorithm +## * `sha1 module<sha1.html>`_ for the SHA-1 checksum algorithm template cbBase(a, b): untyped = [ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', @@ -68,15 +66,11 @@ template cbBase(a, b): untyped = [ 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', a, b] -let +const cb64 = cbBase('+', '/') cb64safe = cbBase('-', '_') const - cb64VM = cbBase('+', '/') - cb64safeVM = cbBase('-', '_') - -const invalidChar = 255 template encodeSize(size: int): int = (size * 4 div 3) + 6 @@ -86,10 +80,13 @@ template encodeInternal(s, alphabet: typed): untyped = result.setLen(encodeSize(s.len)) + let + padding = s.len mod 3 + inputEnds = s.len - padding + var inputIndex = 0 outputIndex = 0 - inputEnds = s.len - s.len mod 3 n: uint32 b: uint32 @@ -115,7 +112,6 @@ template encodeInternal(s, alphabet: typed): untyped = outputChar(n shr 6) outputChar(n shr 0) - var padding = s.len mod 3 if padding == 1: inputByte(b shl 16) outputChar(n shr 18) @@ -134,21 +130,14 @@ template encodeInternal(s, alphabet: typed): untyped = result.setLen(outputIndex) template encodeImpl() {.dirty.} = - when nimVM: - block: - let lookupTableVM = if safe: cb64safeVM else: cb64VM - encodeInternal(s, lookupTableVM) + if safe: + encodeInternal(s, cb64safe) else: - block: - let lookupTable = if safe: unsafeAddr(cb64safe) else: unsafeAddr(cb64) - encodeInternal(s, lookupTable) + encodeInternal(s, cb64) -proc encode*[T: SomeInteger|char](s: openArray[T], safe = false): string = +proc encode*[T: byte|char](s: openArray[T], safe = false): string = ## Encodes `s` into base64 representation. ## - ## This procedure encodes an openarray (array or sequence) of either integers - ## or characters. - ## ## If `safe` is `true` then it will encode using the ## URL-Safe and Filesystem-safe standard alphabet characters, ## which substitutes `-` instead of `+` and `_` instead of `/`. @@ -156,18 +145,24 @@ proc encode*[T: SomeInteger|char](s: openArray[T], safe = false): string = ## * https://tools.ietf.org/html/rfc4648#page-7 ## ## **See also:** - ## * `encode proc<#encode,string>`_ for encoding a string ## * `decode proc<#decode,string>`_ for decoding a string runnableExamples: + assert encode("Hello World") == "SGVsbG8gV29ybGQ=" assert encode(['n', 'i', 'm']) == "bmlt" assert encode(@['n', 'i', 'm']) == "bmlt" - assert encode([1, 2, 3, 4, 5]) == "AQIDBAU=" + assert encode([1'u8, 2, 3, 4, 5]) == "AQIDBAU=" encodeImpl() -proc encode*(s: string, safe = false): string = - ## Encodes `s` into base64 representation. +proc encode*[T: SomeInteger and not byte](s: openArray[T], safe = false): string + {.deprecated: "use `byte` or `char` instead".} = + encodeImpl() + +proc encodeMime*(s: string, lineLen = 75.Positive, newLine = "\r\n", + safe = false): string = + ## Encodes `s` into base64 representation as lines. + ## Used in email MIME format, use `lineLen` and `newline`. ## - ## This procedure encodes a string. + ## This procedure encodes a string according to MIME spec. ## ## If `safe` is `true` then it will encode using the ## URL-Safe and Filesystem-safe standard alphabet characters, @@ -176,28 +171,29 @@ proc encode*(s: string, safe = false): string = ## * https://tools.ietf.org/html/rfc4648#page-7 ## ## **See also:** - ## * `encode proc<#encode,openArray[T]>`_ for encoding an openarray - ## * `decode proc<#decode,string>`_ for decoding a string - runnableExamples: - assert encode("Hello World") == "SGVsbG8gV29ybGQ=" - encodeImpl() - -proc encodeMime*(s: string, lineLen = 75, newLine = "\r\n"): string = - ## Encodes `s` into base64 representation as lines. - ## Used in email MIME format, use `lineLen` and `newline`. - ## - ## This procedure encodes a string according to MIME spec. - ## - ## **See also:** - ## * `encode proc<#encode,string>`_ for encoding a string + ## * `encode proc<#encode,openArray[T]>`_ for encoding an openArray ## * `decode proc<#decode,string>`_ for decoding a string runnableExamples: assert encodeMime("Hello World", 4, "\n") == "SGVs\nbG8g\nV29y\nbGQ=" - result = newStringOfCap(encodeSize(s.len)) - for i, c in encode(s): - if i != 0 and (i mod lineLen == 0): - result.add(newLine) - result.add(c) + template cpy(l, src, idx) = + b = l + while i < b: + result[i] = src[idx] + inc i + inc idx + + if s.len == 0: return + let e = encode(s, safe) + if e.len <= lineLen or newLine.len == 0: + return e + result = newString(e.len + newLine.len * ((e.len div lineLen) - int(e.len mod lineLen == 0))) + var i, j, k, b: int + let nd = e.len - lineLen + while j < nd: + cpy(i + lineLen, e, j) + cpy(i + newLine.len, newLine, k) + k = 0 + cpy(result.len, e, j) proc initDecodeTable*(): array[256, char] = # computes a decode table at compile time @@ -220,7 +216,6 @@ proc decode*(s: string): string = ## ## **See also:** ## * `encode proc<#encode,openArray[T]>`_ for encoding an openarray - ## * `encode proc<#encode,string>`_ for encoding a string runnableExamples: assert decode("SGVsbG8gV29ybGQ=") == "Hello World" assert decode(" SGVsbG8gV29ybGQ=") == "Hello World" @@ -249,7 +244,7 @@ proc decode*(s: string): string = inputLen = s.len inputEnds = 0 # strip trailing characters - while s[inputLen - 1] in {'\n', '\r', ' ', '='}: + while inputLen > 0 and s[inputLen - 1] in {'\n', '\r', ' ', '='}: dec inputLen # hot loop: read 4 characters at at time inputEnds = inputLen - 4 |