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- /*
- * Copyright 2006 The Android Open Source Project
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
- #include "include/utils/SkBase64.h"
- #define DecodePad -2
- #define EncodePad 64
- static const char default_encode[] =
- "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
- "abcdefghijklmnopqrstuvwxyz"
- "0123456789+/=";
- static const signed char decodeData[] = {
- 62, -1, -1, -1, 63,
- 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, DecodePad, -1, -1,
- -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
- 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
- -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
- 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
- };
- SkBase64::SkBase64() : fLength((size_t) -1), fData(nullptr) {
- }
- #if defined _WIN32 // disable 'two', etc. may be used without having been initialized
- #pragma warning ( push )
- #pragma warning ( disable : 4701 )
- #endif
- SkBase64::Error SkBase64::decode(const void* srcPtr, size_t size, bool writeDestination) {
- unsigned char* dst = (unsigned char*) fData;
- const unsigned char* dstStart = (const unsigned char*) fData;
- const unsigned char* src = (const unsigned char*) srcPtr;
- bool padTwo = false;
- bool padThree = false;
- const unsigned char* end = src + size;
- while (src < end) {
- unsigned char bytes[4];
- int byte = 0;
- do {
- unsigned char srcByte = *src++;
- if (srcByte == 0)
- goto goHome;
- if (srcByte <= ' ')
- continue; // treat as white space
- if (srcByte < '+' || srcByte > 'z')
- return kBadCharError;
- signed char decoded = decodeData[srcByte - '+'];
- bytes[byte] = decoded;
- if (decoded < 0) {
- if (decoded == DecodePad)
- goto handlePad;
- return kBadCharError;
- } else
- byte++;
- if (*src)
- continue;
- if (byte == 0)
- goto goHome;
- if (byte == 4)
- break;
- handlePad:
- if (byte < 2)
- return kPadError;
- padThree = true;
- if (byte == 2)
- padTwo = true;
- break;
- } while (byte < 4);
- int two = 0;
- int three = 0;
- if (writeDestination) {
- int one = (uint8_t) (bytes[0] << 2);
- two = bytes[1];
- one |= two >> 4;
- two = (uint8_t) ((two << 4) & 0xFF);
- three = bytes[2];
- two |= three >> 2;
- three = (uint8_t) ((three << 6) & 0xFF);
- three |= bytes[3];
- SkASSERT(one < 256 && two < 256 && three < 256);
- *dst = (unsigned char) one;
- }
- dst++;
- if (padTwo)
- break;
- if (writeDestination)
- *dst = (unsigned char) two;
- dst++;
- if (padThree)
- break;
- if (writeDestination)
- *dst = (unsigned char) three;
- dst++;
- }
- goHome:
- fLength = dst - dstStart;
- return kNoError;
- }
- #if defined _WIN32
- #pragma warning ( pop )
- #endif
- size_t SkBase64::Encode(const void* srcPtr, size_t length, void* dstPtr, const char* encodeMap) {
- const char* encode;
- if (nullptr == encodeMap) {
- encode = default_encode;
- } else {
- encode = encodeMap;
- }
- const unsigned char* src = (const unsigned char*) srcPtr;
- unsigned char* dst = (unsigned char*) dstPtr;
- if (dst) {
- size_t remainder = length % 3;
- const unsigned char* end = &src[length - remainder];
- while (src < end) {
- unsigned a = *src++;
- unsigned b = *src++;
- unsigned c = *src++;
- int d = c & 0x3F;
- c = (c >> 6 | b << 2) & 0x3F;
- b = (b >> 4 | a << 4) & 0x3F;
- a = a >> 2;
- *dst++ = encode[a];
- *dst++ = encode[b];
- *dst++ = encode[c];
- *dst++ = encode[d];
- }
- if (remainder > 0) {
- int k1 = 0;
- int k2 = EncodePad;
- int a = (uint8_t) *src++;
- if (remainder == 2)
- {
- int b = *src++;
- k1 = b >> 4;
- k2 = (b << 2) & 0x3F;
- }
- *dst++ = encode[a >> 2];
- *dst++ = encode[(k1 | a << 4) & 0x3F];
- *dst++ = encode[k2];
- *dst++ = encode[EncodePad];
- }
- }
- return (length + 2) / 3 * 4;
- }
- SkBase64::Error SkBase64::decode(const char* src, size_t len) {
- Error err = decode(src, len, false);
- SkASSERT(err == kNoError);
- if (err != kNoError)
- return err;
- fData = new char[fLength]; // should use sk_malloc/sk_free
- decode(src, len, true);
- return kNoError;
- }
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