diff options
Diffstat (limited to 'deps/node/deps/icu-small/source/common/unicode/bytestrie.h')
| -rw-r--r-- | deps/node/deps/icu-small/source/common/unicode/bytestrie.h | 520 |
1 files changed, 0 insertions, 520 deletions
diff --git a/deps/node/deps/icu-small/source/common/unicode/bytestrie.h b/deps/node/deps/icu-small/source/common/unicode/bytestrie.h deleted file mode 100644 index c57b8ccf..00000000 --- a/deps/node/deps/icu-small/source/common/unicode/bytestrie.h +++ /dev/null @@ -1,520 +0,0 @@ -// © 2016 and later: Unicode, Inc. and others. -// License & terms of use: http://www.unicode.org/copyright.html -/* -******************************************************************************* -* Copyright (C) 2010-2012, International Business Machines -* Corporation and others. All Rights Reserved. -******************************************************************************* -* file name: bytestrie.h -* encoding: UTF-8 -* tab size: 8 (not used) -* indentation:4 -* -* created on: 2010sep25 -* created by: Markus W. Scherer -*/ - -#ifndef __BYTESTRIE_H__ -#define __BYTESTRIE_H__ - -/** - * \file - * \brief C++ API: Trie for mapping byte sequences to integer values. - */ - -#include "unicode/utypes.h" -#include "unicode/stringpiece.h" -#include "unicode/uobject.h" -#include "unicode/ustringtrie.h" - -U_NAMESPACE_BEGIN - -class ByteSink; -class BytesTrieBuilder; -class CharString; -class UVector32; - -/** - * Light-weight, non-const reader class for a BytesTrie. - * Traverses a byte-serialized data structure with minimal state, - * for mapping byte sequences to non-negative integer values. - * - * This class owns the serialized trie data only if it was constructed by - * the builder's build() method. - * The public constructor and the copy constructor only alias the data (only copy the pointer). - * There is no assignment operator. - * - * This class is not intended for public subclassing. - * @stable ICU 4.8 - */ -class U_COMMON_API BytesTrie : public UMemory { -public: - /** - * Constructs a BytesTrie reader instance. - * - * The trieBytes must contain a copy of a byte sequence from the BytesTrieBuilder, - * starting with the first byte of that sequence. - * The BytesTrie object will not read more bytes than - * the BytesTrieBuilder generated in the corresponding build() call. - * - * The array is not copied/cloned and must not be modified while - * the BytesTrie object is in use. - * - * @param trieBytes The byte array that contains the serialized trie. - * @stable ICU 4.8 - */ - BytesTrie(const void *trieBytes) - : ownedArray_(NULL), bytes_(static_cast<const uint8_t *>(trieBytes)), - pos_(bytes_), remainingMatchLength_(-1) {} - - /** - * Destructor. - * @stable ICU 4.8 - */ - ~BytesTrie(); - - /** - * Copy constructor, copies the other trie reader object and its state, - * but not the byte array which will be shared. (Shallow copy.) - * @param other Another BytesTrie object. - * @stable ICU 4.8 - */ - BytesTrie(const BytesTrie &other) - : ownedArray_(NULL), bytes_(other.bytes_), - pos_(other.pos_), remainingMatchLength_(other.remainingMatchLength_) {} - - /** - * Resets this trie to its initial state. - * @return *this - * @stable ICU 4.8 - */ - BytesTrie &reset() { - pos_=bytes_; - remainingMatchLength_=-1; - return *this; - } - - /** - * BytesTrie state object, for saving a trie's current state - * and resetting the trie back to this state later. - * @stable ICU 4.8 - */ - class State : public UMemory { - public: - /** - * Constructs an empty State. - * @stable ICU 4.8 - */ - State() { bytes=NULL; } - private: - friend class BytesTrie; - - const uint8_t *bytes; - const uint8_t *pos; - int32_t remainingMatchLength; - }; - - /** - * Saves the state of this trie. - * @param state The State object to hold the trie's state. - * @return *this - * @see resetToState - * @stable ICU 4.8 - */ - const BytesTrie &saveState(State &state) const { - state.bytes=bytes_; - state.pos=pos_; - state.remainingMatchLength=remainingMatchLength_; - return *this; - } - - /** - * Resets this trie to the saved state. - * If the state object contains no state, or the state of a different trie, - * then this trie remains unchanged. - * @param state The State object which holds a saved trie state. - * @return *this - * @see saveState - * @see reset - * @stable ICU 4.8 - */ - BytesTrie &resetToState(const State &state) { - if(bytes_==state.bytes && bytes_!=NULL) { - pos_=state.pos; - remainingMatchLength_=state.remainingMatchLength; - } - return *this; - } - - /** - * Determines whether the byte sequence so far matches, whether it has a value, - * and whether another input byte can continue a matching byte sequence. - * @return The match/value Result. - * @stable ICU 4.8 - */ - UStringTrieResult current() const; - - /** - * Traverses the trie from the initial state for this input byte. - * Equivalent to reset().next(inByte). - * @param inByte Input byte value. Values -0x100..-1 are treated like 0..0xff. - * Values below -0x100 and above 0xff will never match. - * @return The match/value Result. - * @stable ICU 4.8 - */ - inline UStringTrieResult first(int32_t inByte) { - remainingMatchLength_=-1; - if(inByte<0) { - inByte+=0x100; - } - return nextImpl(bytes_, inByte); - } - - /** - * Traverses the trie from the current state for this input byte. - * @param inByte Input byte value. Values -0x100..-1 are treated like 0..0xff. - * Values below -0x100 and above 0xff will never match. - * @return The match/value Result. - * @stable ICU 4.8 - */ - UStringTrieResult next(int32_t inByte); - - /** - * Traverses the trie from the current state for this byte sequence. - * Equivalent to - * \code - * Result result=current(); - * for(each c in s) - * if(!USTRINGTRIE_HAS_NEXT(result)) return USTRINGTRIE_NO_MATCH; - * result=next(c); - * return result; - * \endcode - * @param s A string or byte sequence. Can be NULL if length is 0. - * @param length The length of the byte sequence. Can be -1 if NUL-terminated. - * @return The match/value Result. - * @stable ICU 4.8 - */ - UStringTrieResult next(const char *s, int32_t length); - - /** - * Returns a matching byte sequence's value if called immediately after - * current()/first()/next() returned USTRINGTRIE_INTERMEDIATE_VALUE or USTRINGTRIE_FINAL_VALUE. - * getValue() can be called multiple times. - * - * Do not call getValue() after USTRINGTRIE_NO_MATCH or USTRINGTRIE_NO_VALUE! - * @return The value for the byte sequence so far. - * @stable ICU 4.8 - */ - inline int32_t getValue() const { - const uint8_t *pos=pos_; - int32_t leadByte=*pos++; - // U_ASSERT(leadByte>=kMinValueLead); - return readValue(pos, leadByte>>1); - } - - /** - * Determines whether all byte sequences reachable from the current state - * map to the same value. - * @param uniqueValue Receives the unique value, if this function returns TRUE. - * (output-only) - * @return TRUE if all byte sequences reachable from the current state - * map to the same value. - * @stable ICU 4.8 - */ - inline UBool hasUniqueValue(int32_t &uniqueValue) const { - const uint8_t *pos=pos_; - // Skip the rest of a pending linear-match node. - return pos!=NULL && findUniqueValue(pos+remainingMatchLength_+1, FALSE, uniqueValue); - } - - /** - * Finds each byte which continues the byte sequence from the current state. - * That is, each byte b for which it would be next(b)!=USTRINGTRIE_NO_MATCH now. - * @param out Each next byte is appended to this object. - * (Only uses the out.Append(s, length) method.) - * @return the number of bytes which continue the byte sequence from here - * @stable ICU 4.8 - */ - int32_t getNextBytes(ByteSink &out) const; - - /** - * Iterator for all of the (byte sequence, value) pairs in a BytesTrie. - * @stable ICU 4.8 - */ - class U_COMMON_API Iterator : public UMemory { - public: - /** - * Iterates from the root of a byte-serialized BytesTrie. - * @param trieBytes The trie bytes. - * @param maxStringLength If 0, the iterator returns full strings/byte sequences. - * Otherwise, the iterator returns strings with this maximum length. - * @param errorCode Standard ICU error code. Its input value must - * pass the U_SUCCESS() test, or else the function returns - * immediately. Check for U_FAILURE() on output or use with - * function chaining. (See User Guide for details.) - * @stable ICU 4.8 - */ - Iterator(const void *trieBytes, int32_t maxStringLength, UErrorCode &errorCode); - - /** - * Iterates from the current state of the specified BytesTrie. - * @param trie The trie whose state will be copied for iteration. - * @param maxStringLength If 0, the iterator returns full strings/byte sequences. - * Otherwise, the iterator returns strings with this maximum length. - * @param errorCode Standard ICU error code. Its input value must - * pass the U_SUCCESS() test, or else the function returns - * immediately. Check for U_FAILURE() on output or use with - * function chaining. (See User Guide for details.) - * @stable ICU 4.8 - */ - Iterator(const BytesTrie &trie, int32_t maxStringLength, UErrorCode &errorCode); - - /** - * Destructor. - * @stable ICU 4.8 - */ - ~Iterator(); - - /** - * Resets this iterator to its initial state. - * @return *this - * @stable ICU 4.8 - */ - Iterator &reset(); - - /** - * @return TRUE if there are more elements. - * @stable ICU 4.8 - */ - UBool hasNext() const; - - /** - * Finds the next (byte sequence, value) pair if there is one. - * - * If the byte sequence is truncated to the maximum length and does not - * have a real value, then the value is set to -1. - * In this case, this "not a real value" is indistinguishable from - * a real value of -1. - * @param errorCode Standard ICU error code. Its input value must - * pass the U_SUCCESS() test, or else the function returns - * immediately. Check for U_FAILURE() on output or use with - * function chaining. (See User Guide for details.) - * @return TRUE if there is another element. - * @stable ICU 4.8 - */ - UBool next(UErrorCode &errorCode); - - /** - * @return The NUL-terminated byte sequence for the last successful next(). - * @stable ICU 4.8 - */ - StringPiece getString() const; - /** - * @return The value for the last successful next(). - * @stable ICU 4.8 - */ - int32_t getValue() const { return value_; } - - private: - UBool truncateAndStop(); - - const uint8_t *branchNext(const uint8_t *pos, int32_t length, UErrorCode &errorCode); - - const uint8_t *bytes_; - const uint8_t *pos_; - const uint8_t *initialPos_; - int32_t remainingMatchLength_; - int32_t initialRemainingMatchLength_; - - CharString *str_; - int32_t maxLength_; - int32_t value_; - - // The stack stores pairs of integers for backtracking to another - // outbound edge of a branch node. - // The first integer is an offset from bytes_. - // The second integer has the str_->length() from before the node in bits 15..0, - // and the remaining branch length in bits 24..16. (Bits 31..25 are unused.) - // (We could store the remaining branch length minus 1 in bits 23..16 and not use bits 31..24, - // but the code looks more confusing that way.) - UVector32 *stack_; - }; - -private: - friend class BytesTrieBuilder; - - /** - * Constructs a BytesTrie reader instance. - * Unlike the public constructor which just aliases an array, - * this constructor adopts the builder's array. - * This constructor is only called by the builder. - */ - BytesTrie(void *adoptBytes, const void *trieBytes) - : ownedArray_(static_cast<uint8_t *>(adoptBytes)), - bytes_(static_cast<const uint8_t *>(trieBytes)), - pos_(bytes_), remainingMatchLength_(-1) {} - - // No assignment operator. - BytesTrie &operator=(const BytesTrie &other); - - inline void stop() { - pos_=NULL; - } - - // Reads a compact 32-bit integer. - // pos is already after the leadByte, and the lead byte is already shifted right by 1. - static int32_t readValue(const uint8_t *pos, int32_t leadByte); - static inline const uint8_t *skipValue(const uint8_t *pos, int32_t leadByte) { - // U_ASSERT(leadByte>=kMinValueLead); - if(leadByte>=(kMinTwoByteValueLead<<1)) { - if(leadByte<(kMinThreeByteValueLead<<1)) { - ++pos; - } else if(leadByte<(kFourByteValueLead<<1)) { - pos+=2; - } else { - pos+=3+((leadByte>>1)&1); - } - } - return pos; - } - static inline const uint8_t *skipValue(const uint8_t *pos) { - int32_t leadByte=*pos++; - return skipValue(pos, leadByte); - } - - // Reads a jump delta and jumps. - static const uint8_t *jumpByDelta(const uint8_t *pos); - - static inline const uint8_t *skipDelta(const uint8_t *pos) { - int32_t delta=*pos++; - if(delta>=kMinTwoByteDeltaLead) { - if(delta<kMinThreeByteDeltaLead) { - ++pos; - } else if(delta<kFourByteDeltaLead) { - pos+=2; - } else { - pos+=3+(delta&1); - } - } - return pos; - } - - static inline UStringTrieResult valueResult(int32_t node) { - return (UStringTrieResult)(USTRINGTRIE_INTERMEDIATE_VALUE-(node&kValueIsFinal)); - } - - // Handles a branch node for both next(byte) and next(string). - UStringTrieResult branchNext(const uint8_t *pos, int32_t length, int32_t inByte); - - // Requires remainingLength_<0. - UStringTrieResult nextImpl(const uint8_t *pos, int32_t inByte); - - // Helper functions for hasUniqueValue(). - // Recursively finds a unique value (or whether there is not a unique one) - // from a branch. - static const uint8_t *findUniqueValueFromBranch(const uint8_t *pos, int32_t length, - UBool haveUniqueValue, int32_t &uniqueValue); - // Recursively finds a unique value (or whether there is not a unique one) - // starting from a position on a node lead byte. - static UBool findUniqueValue(const uint8_t *pos, UBool haveUniqueValue, int32_t &uniqueValue); - - // Helper functions for getNextBytes(). - // getNextBytes() when pos is on a branch node. - static void getNextBranchBytes(const uint8_t *pos, int32_t length, ByteSink &out); - static void append(ByteSink &out, int c); - - // BytesTrie data structure - // - // The trie consists of a series of byte-serialized nodes for incremental - // string/byte sequence matching. The root node is at the beginning of the trie data. - // - // Types of nodes are distinguished by their node lead byte ranges. - // After each node, except a final-value node, another node follows to - // encode match values or continue matching further bytes. - // - // Node types: - // - Value node: Stores a 32-bit integer in a compact, variable-length format. - // The value is for the string/byte sequence so far. - // One node bit indicates whether the value is final or whether - // matching continues with the next node. - // - Linear-match node: Matches a number of bytes. - // - Branch node: Branches to other nodes according to the current input byte. - // The node byte is the length of the branch (number of bytes to select from) - // minus 1. It is followed by a sub-node: - // - If the length is at most kMaxBranchLinearSubNodeLength, then - // there are length-1 (key, value) pairs and then one more comparison byte. - // If one of the key bytes matches, then the value is either a final value for - // the string/byte sequence so far, or a "jump" delta to the next node. - // If the last byte matches, then matching continues with the next node. - // (Values have the same encoding as value nodes.) - // - If the length is greater than kMaxBranchLinearSubNodeLength, then - // there is one byte and one "jump" delta. - // If the input byte is less than the sub-node byte, then "jump" by delta to - // the next sub-node which will have a length of length/2. - // (The delta has its own compact encoding.) - // Otherwise, skip the "jump" delta to the next sub-node - // which will have a length of length-length/2. - - // Node lead byte values. - - // 00..0f: Branch node. If node!=0 then the length is node+1, otherwise - // the length is one more than the next byte. - - // For a branch sub-node with at most this many entries, we drop down - // to a linear search. - static const int32_t kMaxBranchLinearSubNodeLength=5; - - // 10..1f: Linear-match node, match 1..16 bytes and continue reading the next node. - static const int32_t kMinLinearMatch=0x10; - static const int32_t kMaxLinearMatchLength=0x10; - - // 20..ff: Variable-length value node. - // If odd, the value is final. (Otherwise, intermediate value or jump delta.) - // Then shift-right by 1 bit. - // The remaining lead byte value indicates the number of following bytes (0..4) - // and contains the value's top bits. - static const int32_t kMinValueLead=kMinLinearMatch+kMaxLinearMatchLength; // 0x20 - // It is a final value if bit 0 is set. - static const int32_t kValueIsFinal=1; - - // Compact value: After testing bit 0, shift right by 1 and then use the following thresholds. - static const int32_t kMinOneByteValueLead=kMinValueLead/2; // 0x10 - static const int32_t kMaxOneByteValue=0x40; // At least 6 bits in the first byte. - - static const int32_t kMinTwoByteValueLead=kMinOneByteValueLead+kMaxOneByteValue+1; // 0x51 - static const int32_t kMaxTwoByteValue=0x1aff; - - static const int32_t kMinThreeByteValueLead=kMinTwoByteValueLead+(kMaxTwoByteValue>>8)+1; // 0x6c - static const int32_t kFourByteValueLead=0x7e; - - // A little more than Unicode code points. (0x11ffff) - static const int32_t kMaxThreeByteValue=((kFourByteValueLead-kMinThreeByteValueLead)<<16)-1; - - static const int32_t kFiveByteValueLead=0x7f; - - // Compact delta integers. - static const int32_t kMaxOneByteDelta=0xbf; - static const int32_t kMinTwoByteDeltaLead=kMaxOneByteDelta+1; // 0xc0 - static const int32_t kMinThreeByteDeltaLead=0xf0; - static const int32_t kFourByteDeltaLead=0xfe; - static const int32_t kFiveByteDeltaLead=0xff; - - static const int32_t kMaxTwoByteDelta=((kMinThreeByteDeltaLead-kMinTwoByteDeltaLead)<<8)-1; // 0x2fff - static const int32_t kMaxThreeByteDelta=((kFourByteDeltaLead-kMinThreeByteDeltaLead)<<16)-1; // 0xdffff - - uint8_t *ownedArray_; - - // Fixed value referencing the BytesTrie bytes. - const uint8_t *bytes_; - - // Iterator variables. - - // Pointer to next trie byte to read. NULL if no more matches. - const uint8_t *pos_; - // Remaining length of a linear-match node, minus 1. Negative if not in such a node. - int32_t remainingMatchLength_; -}; - -U_NAMESPACE_END - -#endif // __BYTESTRIE_H__ |