Check in the pristine copy of ICU 51.2

icu51/source/common/bytestrie.cpp

Index: icu51/source/common/bytestrie.cpp
===================================================================
--- icu51/source/common/bytestrie.cpp	(revision 0)
+++ icu51/source/common/bytestrie.cpp	(revision 0)
@@ -0,0 +1,439 @@
+/*
+*******************************************************************************
+*   Copyright (C) 2010-2011, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*******************************************************************************
+*   file name:  bytestrie.cpp
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2010sep25
+*   created by: Markus W. Scherer
+*/
+
+#include "unicode/utypes.h"
+#include "unicode/bytestream.h"
+#include "unicode/bytestrie.h"
+#include "unicode/uobject.h"
+#include "cmemory.h"
+#include "uassert.h"
+
+U_NAMESPACE_BEGIN
+
+BytesTrie::~BytesTrie() {
+    uprv_free(ownedArray_);
+}
+
+// lead byte already shifted right by 1.
+int32_t
+BytesTrie::readValue(const uint8_t *pos, int32_t leadByte) {
+    int32_t value;
+    if(leadByte<kMinTwoByteValueLead) {
+        value=leadByte-kMinOneByteValueLead;
+    } else if(leadByte<kMinThreeByteValueLead) {
+        value=((leadByte-kMinTwoByteValueLead)<<8)|*pos;
+    } else if(leadByte<kFourByteValueLead) {
+        value=((leadByte-kMinThreeByteValueLead)<<16)|(pos[0]<<8)|pos[1];
+    } else if(leadByte==kFourByteValueLead) {
+        value=(pos[0]<<16)|(pos[1]<<8)|pos[2];
+    } else {
+        value=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];
+    }
+    return value;
+}
+
+const uint8_t *
+BytesTrie::jumpByDelta(const uint8_t *pos) {
+    int32_t delta=*pos++;
+    if(delta<kMinTwoByteDeltaLead) {
+        // nothing to do
+    } else if(delta<kMinThreeByteDeltaLead) {
+        delta=((delta-kMinTwoByteDeltaLead)<<8)|*pos++;
+    } else if(delta<kFourByteDeltaLead) {
+        delta=((delta-kMinThreeByteDeltaLead)<<16)|(pos[0]<<8)|pos[1];
+        pos+=2;
+    } else if(delta==kFourByteDeltaLead) {
+        delta=(pos[0]<<16)|(pos[1]<<8)|pos[2];
+        pos+=3;
+    } else {
+        delta=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];
+        pos+=4;
+    }
+    return pos+delta;
+}
+
+UStringTrieResult
+BytesTrie::current() const {
+    const uint8_t *pos=pos_;
+    if(pos==NULL) {
+        return USTRINGTRIE_NO_MATCH;
+    } else {
+        int32_t node;
+        return (remainingMatchLength_<0 && (node=*pos)>=kMinValueLead) ?
+                valueResult(node) : USTRINGTRIE_NO_VALUE;
+    }
+}
+
+UStringTrieResult
+BytesTrie::branchNext(const uint8_t *pos, int32_t length, int32_t inByte) {
+    // Branch according to the current byte.
+    if(length==0) {
+        length=*pos++;
+    }
+    ++length;
+    // The length of the branch is the number of bytes to select from.
+    // The data structure encodes a binary search.
+    while(length>kMaxBranchLinearSubNodeLength) {
+        if(inByte<*pos++) {
+            length>>=1;
+            pos=jumpByDelta(pos);
+        } else {
+            length=length-(length>>1);
+            pos=skipDelta(pos);
+        }
+    }
+    // Drop down to linear search for the last few bytes.
+    // length>=2 because the loop body above sees length>kMaxBranchLinearSubNodeLength>=3
+    // and divides length by 2.
+    do {
+        if(inByte==*pos++) {
+            UStringTrieResult result;
+            int32_t node=*pos;
+            U_ASSERT(node>=kMinValueLead);
+            if(node&kValueIsFinal) {
+                // Leave the final value for getValue() to read.
+                result=USTRINGTRIE_FINAL_VALUE;
+            } else {
+                // Use the non-final value as the jump delta.
+                ++pos;
+                // int32_t delta=readValue(pos, node>>1);
+                node>>=1;
+                int32_t delta;
+                if(node<kMinTwoByteValueLead) {
+                    delta=node-kMinOneByteValueLead;
+                } else if(node<kMinThreeByteValueLead) {
+                    delta=((node-kMinTwoByteValueLead)<<8)|*pos++;
+                } else if(node<kFourByteValueLead) {
+                    delta=((node-kMinThreeByteValueLead)<<16)|(pos[0]<<8)|pos[1];
+                    pos+=2;
+                } else if(node==kFourByteValueLead) {
+                    delta=(pos[0]<<16)|(pos[1]<<8)|pos[2];
+                    pos+=3;
+                } else {
+                    delta=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];
+                    pos+=4;
+                }
+                // end readValue()
+                pos+=delta;
+                node=*pos;
+                result= node>=kMinValueLead ? valueResult(node) : USTRINGTRIE_NO_VALUE;
+            }
+            pos_=pos;
+            return result;
+        }
+        --length;
+        pos=skipValue(pos);
+    } while(length>1);
+    if(inByte==*pos++) {
+        pos_=pos;
+        int32_t node=*pos;
+        return node>=kMinValueLead ? valueResult(node) : USTRINGTRIE_NO_VALUE;
+    } else {
+        stop();
+        return USTRINGTRIE_NO_MATCH;
+    }
+}
+
+UStringTrieResult
+BytesTrie::nextImpl(const uint8_t *pos, int32_t inByte) {
+    for(;;) {
+        int32_t node=*pos++;
+        if(node<kMinLinearMatch) {
+            return branchNext(pos, node, inByte);
+        } else if(node<kMinValueLead) {
+            // Match the first of length+1 bytes.
+            int32_t length=node-kMinLinearMatch;  // Actual match length minus 1.
+            if(inByte==*pos++) {
+                remainingMatchLength_=--length;
+                pos_=pos;
+                return (length<0 && (node=*pos)>=kMinValueLead) ?
+                        valueResult(node) : USTRINGTRIE_NO_VALUE;
+            } else {
+                // No match.
+                break;
+            }
+        } else if(node&kValueIsFinal) {
+            // No further matching bytes.
+            break;
+        } else {
+            // Skip intermediate value.
+            pos=skipValue(pos, node);
+            // The next node must not also be a value node.
+            U_ASSERT(*pos<kMinValueLead);
+        }
+    }
+    stop();
+    return USTRINGTRIE_NO_MATCH;
+}
+
+UStringTrieResult
+BytesTrie::next(int32_t inByte) {
+    const uint8_t *pos=pos_;
+    if(pos==NULL) {
+        return USTRINGTRIE_NO_MATCH;
+    }
+    if(inByte<0) {
+        inByte+=0x100;
+    }
+    int32_t length=remainingMatchLength_;  // Actual remaining match length minus 1.
+    if(length>=0) {
+        // Remaining part of a linear-match node.
+        if(inByte==*pos++) {
+            remainingMatchLength_=--length;
+            pos_=pos;
+            int32_t node;
+            return (length<0 && (node=*pos)>=kMinValueLead) ?
+                    valueResult(node) : USTRINGTRIE_NO_VALUE;
+        } else {
+            stop();
+            return USTRINGTRIE_NO_MATCH;
+        }
+    }
+    return nextImpl(pos, inByte);
+}
+
+UStringTrieResult
+BytesTrie::next(const char *s, int32_t sLength) {
+    if(sLength<0 ? *s==0 : sLength==0) {
+        // Empty input.
+        return current();
+    }
+    const uint8_t *pos=pos_;
+    if(pos==NULL) {
+        return USTRINGTRIE_NO_MATCH;
+    }
+    int32_t length=remainingMatchLength_;  // Actual remaining match length minus 1.
+    for(;;) {
+        // Fetch the next input byte, if there is one.
+        // Continue a linear-match node without rechecking sLength<0.
+        int32_t inByte;
+        if(sLength<0) {
+            for(;;) {
+                if((inByte=*s++)==0) {
+                    remainingMatchLength_=length;
+                    pos_=pos;
+                    int32_t node;
+                    return (length<0 && (node=*pos)>=kMinValueLead) ?
+                            valueResult(node) : USTRINGTRIE_NO_VALUE;
+                }
+                if(length<0) {
+                    remainingMatchLength_=length;
+                    break;
+                }
+                if(inByte!=*pos) {
+                    stop();
+                    return USTRINGTRIE_NO_MATCH;
+                }
+                ++pos;
+                --length;
+            }
+        } else {
+            for(;;) {
+                if(sLength==0) {
+                    remainingMatchLength_=length;
+                    pos_=pos;
+                    int32_t node;
+                    return (length<0 && (node=*pos)>=kMinValueLead) ?
+                            valueResult(node) : USTRINGTRIE_NO_VALUE;
+                }
+                inByte=*s++;
+                --sLength;
+                if(length<0) {
+                    remainingMatchLength_=length;
+                    break;
+                }
+                if(inByte!=*pos) {
+                    stop();
+                    return USTRINGTRIE_NO_MATCH;
+                }
+                ++pos;
+                --length;
+            }
+        }
+        for(;;) {
+            int32_t node=*pos++;
+            if(node<kMinLinearMatch) {
+                UStringTrieResult result=branchNext(pos, node, inByte);
+                if(result==USTRINGTRIE_NO_MATCH) {
+                    return USTRINGTRIE_NO_MATCH;
+                }
+                // Fetch the next input byte, if there is one.
+                if(sLength<0) {
+                    if((inByte=*s++)==0) {
+                        return result;
+                    }
+                } else {
+                    if(sLength==0) {
+                        return result;
+                    }
+                    inByte=*s++;
+                    --sLength;
+                }
+                if(result==USTRINGTRIE_FINAL_VALUE) {
+                    // No further matching bytes.
+                    stop();
+                    return USTRINGTRIE_NO_MATCH;
+                }
+                pos=pos_;  // branchNext() advanced pos and wrote it to pos_ .
+            } else if(node<kMinValueLead) {
+                // Match length+1 bytes.
+                length=node-kMinLinearMatch;  // Actual match length minus 1.
+                if(inByte!=*pos) {
+                    stop();
+                    return USTRINGTRIE_NO_MATCH;
+                }
+                ++pos;
+                --length;
+                break;
+            } else if(node&kValueIsFinal) {
+                // No further matching bytes.
+                stop();
+                return USTRINGTRIE_NO_MATCH;
+            } else {
+                // Skip intermediate value.
+                pos=skipValue(pos, node);
+                // The next node must not also be a value node.
+                U_ASSERT(*pos<kMinValueLead);
+            }
+        }
+    }
+}
+
+const uint8_t *
+BytesTrie::findUniqueValueFromBranch(const uint8_t *pos, int32_t length,
+                                     UBool haveUniqueValue, int32_t &uniqueValue) {
+    while(length>kMaxBranchLinearSubNodeLength) {
+        ++pos;  // ignore the comparison byte
+        if(NULL==findUniqueValueFromBranch(jumpByDelta(pos), length>>1, haveUniqueValue, uniqueValue)) {
+            return NULL;
+        }
+        length=length-(length>>1);
+        pos=skipDelta(pos);
+    }
+    do {
+        ++pos;  // ignore a comparison byte
+        // handle its value
+        int32_t node=*pos++;
+        UBool isFinal=(UBool)(node&kValueIsFinal);
+        int32_t value=readValue(pos, node>>1);
+        pos=skipValue(pos, node);
+        if(isFinal) {
+            if(haveUniqueValue) {
+                if(value!=uniqueValue) {
+                    return NULL;
+                }
+            } else {
+                uniqueValue=value;
+                haveUniqueValue=TRUE;
+            }
+        } else {
+            if(!findUniqueValue(pos+value, haveUniqueValue, uniqueValue)) {
+                return NULL;
+            }
+            haveUniqueValue=TRUE;
+        }
+    } while(--length>1);
+    return pos+1;  // ignore the last comparison byte
+}
+
+UBool
+BytesTrie::findUniqueValue(const uint8_t *pos, UBool haveUniqueValue, int32_t &uniqueValue) {
+    for(;;) {
+        int32_t node=*pos++;
+        if(node<kMinLinearMatch) {
+            if(node==0) {
+                node=*pos++;
+            }
+            pos=findUniqueValueFromBranch(pos, node+1, haveUniqueValue, uniqueValue);
+            if(pos==NULL) {
+                return FALSE;
+            }
+            haveUniqueValue=TRUE;
+        } else if(node<kMinValueLead) {
+            // linear-match node
+            pos+=node-kMinLinearMatch+1;  // Ignore the match bytes.
+        } else {
+            UBool isFinal=(UBool)(node&kValueIsFinal);
+            int32_t value=readValue(pos, node>>1);
+            if(haveUniqueValue) {
+                if(value!=uniqueValue) {
+                    return FALSE;
+                }
+            } else {
+                uniqueValue=value;
+                haveUniqueValue=TRUE;
+            }
+            if(isFinal) {
+                return TRUE;
+            }
+            pos=skipValue(pos, node);
+        }
+    }
+}
+
+int32_t
+BytesTrie::getNextBytes(ByteSink &out) const {
+    const uint8_t *pos=pos_;
+    if(pos==NULL) {
+        return 0;
+    }
+    if(remainingMatchLength_>=0) {
+        append(out, *pos);  // Next byte of a pending linear-match node.
+        return 1;
+    }
+    int32_t node=*pos++;
+    if(node>=kMinValueLead) {
+        if(node&kValueIsFinal) {
+            return 0;
+        } else {
+            pos=skipValue(pos, node);
+            node=*pos++;
+            U_ASSERT(node<kMinValueLead);
+        }
+    }
+    if(node<kMinLinearMatch) {
+        if(node==0) {
+            node=*pos++;
+        }
+        getNextBranchBytes(pos, ++node, out);
+        return node;
+    } else {
+        // First byte of the linear-match node.
+        append(out, *pos);
+        return 1;
+    }
+}
+
+void
+BytesTrie::getNextBranchBytes(const uint8_t *pos, int32_t length, ByteSink &out) {
+    while(length>kMaxBranchLinearSubNodeLength) {
+        ++pos;  // ignore the comparison byte
+        getNextBranchBytes(jumpByDelta(pos), length>>1, out);
+        length=length-(length>>1);
+        pos=skipDelta(pos);
+    }
+    do {
+        append(out, *pos++);
+        pos=skipValue(pos);
+    } while(--length>1);
+    append(out, *pos);
+}
+
+void
+BytesTrie::append(ByteSink &out, int c) {
+    char ch=(char)c;
+    out.Append(&ch, 1);
+}
+
+U_NAMESPACE_END
Property changes on: icu51/source/common/bytestrie.cpp
___________________________________________________________________
Added: svn:eol-style
   + LF