Lucene 源码分析集------- Base64

mark下base64的封装源码

const String Base64::BASE64_CHARS = L"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; Base64::~Base64() { } String Base64::encode(ByteArray bytes) { return encode(bytes.get(), bytes.size()); } String Base64::encode(const uint8_t* bytes, int32_t length) { String result; uint8_t byteArray3[3]; uint8_t byteArray4[4]; int32_t i = 0; while (length--) { byteArray3[i++] = *(bytes++); if (i == 3) { byteArray4[0] = (byteArray3[0] & 0xfc) >> 2; byteArray4[1] = ((byteArray3[0] & 0x03) << 4) + ((byteArray3[1] & 0xf0) >> 4); byteArray4[2] = ((byteArray3[1] & 0x0f) << 2) + ((byteArray3[2] & 0xc0) >> 6); byteArray4[3] = byteArray3[2] & 0x3f; for (i = 0; i < 4; ++i) { result += BASE64_CHARS[byteArray4[i]]; } i = 0; } } if (i != 0) { for (int32_t j = i; j < 3; ++j) { byteArray3[j] = 0; } byteArray4[0] = (byteArray3[0] & 0xfc) >> 2; byteArray4[1] = ((byteArray3[0] & 0x03) << 4) + ((byteArray3[1] & 0xf0) >> 4); byteArray4[2] = ((byteArray3[1] & 0x0f) << 2) + ((byteArray3[2] & 0xc0) >> 6); byteArray4[3] = byteArray3[2] & 0x3f; for (int32_t j = 0; j < i + 1; ++j) { result += BASE64_CHARS[byteArray4[j]]; } while (i++ < 3) { result += L'='; } } return result; } ByteArray Base64::decode(const String& str) { int32_t length = str.length(); uint8_t byteArray4[4]; uint8_t byteArray3[3]; int32_t i = 0; int32_t charIndex = 0; ByteArray result(ByteArray::newInstance(length / 2)); int32_t resultIndex = 0; while (length-- && str[charIndex] != L'=' && isBase64(str[charIndex])) { byteArray4[i++] = (uint8_t)str[charIndex++]; if (i == 4) { for (i = 0; i < 4; ++i) { byteArray4[i] = static_cast<uint8_t>(BASE64_CHARS.find(byteArray4[i])); } byteArray3[0] = (byteArray4[0] << 2) + ((byteArray4[1] & 0x30) >> 4); byteArray3[1] = ((byteArray4[1] & 0xf) << 4) + ((byteArray4[2] & 0x3c) >> 2); byteArray3[2] = ((byteArray4[2] & 0x3) << 6) + byteArray4[3]; for (i = 0; i < 3; ++i) { if (resultIndex >= result.size()) { result.resize((int32_t)((double)result.size() * 1.5)); } result[resultIndex++] = byteArray3[i]; } i = 0; } } if (i != 0) { for (int32_t j = i; j < 4; ++j) { byteArray4[j] = 0; } for (int32_t j = 0; j < 4; ++j) { byteArray4[j] = static_cast<uint8_t>(BASE64_CHARS.find(byteArray4[j])); } byteArray3[0] = (byteArray4[0] << 2) + ((byteArray4[1] & 0x30) >> 4); byteArray3[1] = ((byteArray4[1] & 0xf) << 4) + ((byteArray4[2] & 0x3c) >> 2); byteArray3[2] = ((byteArray4[2] & 0x3) << 6) + byteArray4[3]; for (int32_t j = 0; j < i - 1; ++j) { if (resultIndex >= result.size()) { result.resize((int32_t)((double)result.size() * 1.5)); } result[resultIndex++] = byteArray3[j]; } } result.resize(resultIndex); return result; } bool Base64::isBase64(wchar_t ch) { return (UnicodeUtil::isAlnum(ch) || ch == L'+' || ch == L'/'); }