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Diffstat (limited to 'intl/icu/source/i18n/collation.cpp')
-rw-r--r-- | intl/icu/source/i18n/collation.cpp | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/collation.cpp b/intl/icu/source/i18n/collation.cpp new file mode 100644 index 000000000..bac7498df --- /dev/null +++ b/intl/icu/source/i18n/collation.cpp @@ -0,0 +1,150 @@ +// Copyright (C) 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +******************************************************************************* +* Copyright (C) 2010-2014, International Business Machines +* Corporation and others. All Rights Reserved. +******************************************************************************* +* collation.cpp +* +* created on: 2010oct27 +* created by: Markus W. Scherer +*/ + +#include "unicode/utypes.h" + +#if !UCONFIG_NO_COLLATION + +#include "collation.h" +#include "uassert.h" + +U_NAMESPACE_BEGIN + +// Some compilers don't care if constants are defined in the .cpp file. +// MS Visual C++ does not like it, but gcc requires it. clang does not care. +#ifndef _MSC_VER +const uint8_t Collation::LEVEL_SEPARATOR_BYTE; +const uint8_t Collation::MERGE_SEPARATOR_BYTE; +const uint32_t Collation::ONLY_TERTIARY_MASK; +const uint32_t Collation::CASE_AND_TERTIARY_MASK; +#endif + +uint32_t +Collation::incTwoBytePrimaryByOffset(uint32_t basePrimary, UBool isCompressible, int32_t offset) { + // Extract the second byte, minus the minimum byte value, + // plus the offset, modulo the number of usable byte values, plus the minimum. + // Reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary. + uint32_t primary; + if(isCompressible) { + offset += ((int32_t)(basePrimary >> 16) & 0xff) - 4; + primary = (uint32_t)((offset % 251) + 4) << 16; + offset /= 251; + } else { + offset += ((int32_t)(basePrimary >> 16) & 0xff) - 2; + primary = (uint32_t)((offset % 254) + 2) << 16; + offset /= 254; + } + // First byte, assume no further overflow. + return primary | ((basePrimary & 0xff000000) + (uint32_t)(offset << 24)); +} + +uint32_t +Collation::incThreeBytePrimaryByOffset(uint32_t basePrimary, UBool isCompressible, int32_t offset) { + // Extract the third byte, minus the minimum byte value, + // plus the offset, modulo the number of usable byte values, plus the minimum. + offset += ((int32_t)(basePrimary >> 8) & 0xff) - 2; + uint32_t primary = (uint32_t)((offset % 254) + 2) << 8; + offset /= 254; + // Same with the second byte, + // but reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary. + if(isCompressible) { + offset += ((int32_t)(basePrimary >> 16) & 0xff) - 4; + primary |= (uint32_t)((offset % 251) + 4) << 16; + offset /= 251; + } else { + offset += ((int32_t)(basePrimary >> 16) & 0xff) - 2; + primary |= (uint32_t)((offset % 254) + 2) << 16; + offset /= 254; + } + // First byte, assume no further overflow. + return primary | ((basePrimary & 0xff000000) + (uint32_t)(offset << 24)); +} + +uint32_t +Collation::decTwoBytePrimaryByOneStep(uint32_t basePrimary, UBool isCompressible, int32_t step) { + // Extract the second byte, minus the minimum byte value, + // minus the step, modulo the number of usable byte values, plus the minimum. + // Reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary. + // Assume no further underflow for the first byte. + U_ASSERT(0 < step && step <= 0x7f); + int32_t byte2 = ((int32_t)(basePrimary >> 16) & 0xff) - step; + if(isCompressible) { + if(byte2 < 4) { + byte2 += 251; + basePrimary -= 0x1000000; + } + } else { + if(byte2 < 2) { + byte2 += 254; + basePrimary -= 0x1000000; + } + } + return (basePrimary & 0xff000000) | ((uint32_t)byte2 << 16); +} + +uint32_t +Collation::decThreeBytePrimaryByOneStep(uint32_t basePrimary, UBool isCompressible, int32_t step) { + // Extract the third byte, minus the minimum byte value, + // minus the step, modulo the number of usable byte values, plus the minimum. + U_ASSERT(0 < step && step <= 0x7f); + int32_t byte3 = ((int32_t)(basePrimary >> 8) & 0xff) - step; + if(byte3 >= 2) { + return (basePrimary & 0xffff0000) | ((uint32_t)byte3 << 8); + } + byte3 += 254; + // Same with the second byte, + // but reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary. + int32_t byte2 = ((int32_t)(basePrimary >> 16) & 0xff) - 1; + if(isCompressible) { + if(byte2 < 4) { + byte2 = 0xfe; + basePrimary -= 0x1000000; + } + } else { + if(byte2 < 2) { + byte2 = 0xff; + basePrimary -= 0x1000000; + } + } + // First byte, assume no further underflow. + return (basePrimary & 0xff000000) | ((uint32_t)byte2 << 16) | ((uint32_t)byte3 << 8); +} + +uint32_t +Collation::getThreeBytePrimaryForOffsetData(UChar32 c, int64_t dataCE) { + uint32_t p = (uint32_t)(dataCE >> 32); // three-byte primary pppppp00 + int32_t lower32 = (int32_t)dataCE; // base code point b & step s: bbbbbbss (bit 7: isCompressible) + int32_t offset = (c - (lower32 >> 8)) * (lower32 & 0x7f); // delta * increment + UBool isCompressible = (lower32 & 0x80) != 0; + return Collation::incThreeBytePrimaryByOffset(p, isCompressible, offset); +} + +uint32_t +Collation::unassignedPrimaryFromCodePoint(UChar32 c) { + // Create a gap before U+0000. Use c=-1 for [first unassigned]. + ++c; + // Fourth byte: 18 values, every 14th byte value (gap of 13). + uint32_t primary = 2 + (c % 18) * 14; + c /= 18; + // Third byte: 254 values. + primary |= (2 + (c % 254)) << 8; + c /= 254; + // Second byte: 251 values 04..FE excluding the primary compression bytes. + primary |= (4 + (c % 251)) << 16; + // One lead byte covers all code points (c < 0x1182B4 = 1*251*254*18). + return primary | (UNASSIGNED_IMPLICIT_BYTE << 24); +} + +U_NAMESPACE_END + +#endif // !UCONFIG_NO_COLLATION |