initial commit, 4.5 stable

thirdparty/icu4c/common/uvector.h

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+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+**********************************************************************
+*   Copyright (C) 1999-2016, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+**********************************************************************
+*   Date        Name        Description
+*   10/22/99    alan        Creation.  This is an internal header.
+*                           It should not be exported.
+**********************************************************************
+*/
+
+#ifndef UVECTOR_H
+#define UVECTOR_H
+
+#include "unicode/utypes.h"
+#include "unicode/uobject.h"
+#include "cmemory.h"
+#include "uarrsort.h"
+#include "uelement.h"
+
+U_NAMESPACE_BEGIN
+
+/**
+ * Ultralightweight C++ implementation of a `void*` vector
+ * that is (mostly) compatible with java.util.Vector.
+ *
+ * This is a very simple implementation, written to satisfy an
+ * immediate porting need.  As such, it is not completely fleshed out,
+ * and it aims for simplicity and conformity.  Nonetheless, it serves
+ * its purpose (porting code from java that uses java.util.Vector)
+ * well, and it could be easily made into a more robust vector class.
+ *
+ * *Design notes*
+ *
+ * There is index bounds checking, but little is done about it.  If
+ * indices are out of bounds, either nothing happens, or zero is
+ * returned.  We *do* avoid indexing off into the weeds.
+ *
+ * Since we don't have garbage collection, UVector was given the
+ * option to *own* its contents.  To employ this, set a deleter
+ * function.  The deleter is called on a `void *` pointer when that
+ * pointer is released by the vector, either when the vector itself is
+ * destructed, or when a call to `setElementAt()` overwrites an element,
+ * or when a call to remove()` or one of its variants explicitly
+ * removes an element.  If no deleter is set, or the deleter is set to
+ * zero, then it is assumed that the caller will delete elements as
+ * needed.
+ *
+ * *Error Handling* Functions that can fail, from out of memory conditions
+ * for example, include a UErrorCode parameter. Any function called
+ * with an error code already indicating a failure will not modify the
+ * vector in any way.
+ *
+ * For vectors that have a deleter function, any failure in inserting
+ * an element into the vector will instead delete the element that
+ * could not be adopted. This simplifies object ownership
+ * management around calls to `addElement()` and `insertElementAt()`;
+ * error or no, the function always takes ownership of an incoming object
+ * from the caller.
+ *
+ * In order to implement methods such as `contains()` and `indexOf()`,
+ * UVector needs a way to compare objects for equality.  To do so, it
+ * uses a comparison function, or "comparer."  If the comparer is not
+ * set, or is set to zero, then all such methods will act as if the
+ * vector contains no element.  That is, indexOf() will always return
+ * -1, contains() will always return false, etc.
+ *
+ * <p><b>To do</b>
+ *
+ * <p>Improve the handling of index out of bounds errors.
+ *
+ * @author Alan Liu
+ */
+class U_COMMON_API UVector : public UObject {
+    // NOTE: UVector uses the UElement (union of void* and int32_t) as
+    // its basic storage type.  It uses UElementsAreEqual as its
+    // comparison function.  It uses UObjectDeleter as its deleter
+    // function.  This allows sharing of support functions with UHashtable.
+
+private:
+    int32_t count = 0;
+
+    int32_t capacity = 0;
+
+    UElement* elements = nullptr;
+
+    UObjectDeleter *deleter = nullptr;
+
+    UElementsAreEqual *comparer = nullptr;
+
+public:
+    UVector(UErrorCode &status);
+
+    UVector(int32_t initialCapacity, UErrorCode &status);
+
+    UVector(UObjectDeleter *d, UElementsAreEqual *c, UErrorCode &status);
+
+    UVector(UObjectDeleter *d, UElementsAreEqual *c, int32_t initialCapacity, UErrorCode &status);
+
+    virtual ~UVector();
+
+    /**
+     * Assign this object to another (make this a copy of 'other').
+     * Use the 'assign' function to assign each element.
+     */
+    void assign(const UVector& other, UElementAssigner *assign, UErrorCode &ec);
+
+    /**
+     * Compare this vector with another.  They will be considered
+     * equal if they are of the same size and all elements are equal,
+     * as compared using this object's comparer.
+     */
+    bool operator==(const UVector& other) const;
+
+    /**
+     * Equivalent to !operator==()
+     */
+    inline bool operator!=(const UVector& other) const {return !operator==(other);}
+
+    //------------------------------------------------------------
+    // java.util.Vector API
+    //------------------------------------------------------------
+
+    /**
+     * Add an element at the end of the vector.
+     * For use only with vectors that do not adopt their elements, which is to say,
+     * have not set an element deleter function. See `adoptElement()`.
+     */
+    void addElement(void *obj, UErrorCode &status);
+
+    /**
+     * Add an element at the end of the vector.
+     * For use only with vectors that adopt their elements, which is to say,
+     * have set an element deleter function. See `addElement()`.
+     *
+     * If the element cannot be successfully added, it will be deleted. This is
+     * normal ICU _adopt_ behavior - one way or another ownership of the incoming
+     * object is transferred from the caller.
+     *
+     * `addElement()` and `adoptElement()` are separate functions to make it easier
+     * to see what the function is doing at call sites. Having a single combined function,
+     * as in earlier versions of UVector, had proved to be error-prone.
+     */
+    void adoptElement(void *obj, UErrorCode &status);
+
+    void addElement(int32_t elem, UErrorCode &status);
+
+    void setElementAt(void* obj, int32_t index);
+
+    void setElementAt(int32_t elem, int32_t index);
+
+    void insertElementAt(void* obj, int32_t index, UErrorCode &status);
+
+    void insertElementAt(int32_t elem, int32_t index, UErrorCode &status);
+    
+    void* elementAt(int32_t index) const;
+
+    int32_t elementAti(int32_t index) const;
+
+    UBool equals(const UVector &other) const;
+
+    inline void* firstElement() const {return elementAt(0);}
+
+    inline void* lastElement() const {return elementAt(count-1);}
+
+    inline int32_t lastElementi() const {return elementAti(count-1);}
+
+    int32_t indexOf(void* obj, int32_t startIndex = 0) const;
+
+    int32_t indexOf(int32_t obj, int32_t startIndex = 0) const;
+
+    inline UBool contains(void* obj) const {return indexOf(obj) >= 0;}
+
+    inline UBool contains(int32_t obj) const {return indexOf(obj) >= 0;}
+
+    UBool containsAll(const UVector& other) const;
+
+    UBool removeAll(const UVector& other);
+
+    UBool retainAll(const UVector& other);
+
+    void removeElementAt(int32_t index);
+
+    UBool removeElement(void* obj);
+
+    void removeAllElements();
+
+    inline int32_t size() const {return count;}
+
+    inline UBool isEmpty() const {return count == 0;}
+
+    UBool ensureCapacity(int32_t minimumCapacity, UErrorCode &status);
+
+    /**
+     * Change the size of this vector as follows: If newSize is
+     * smaller, then truncate the array, possibly deleting held
+     * elements for i >= newSize.  If newSize is larger, grow the
+     * array, filling in new slots with nullptr.
+     */
+    void setSize(int32_t newSize, UErrorCode &status);
+
+    /**
+     * Fill in the given array with all elements of this vector.
+     */
+    void** toArray(void** result) const;
+
+    //------------------------------------------------------------
+    // New API
+    //------------------------------------------------------------
+
+    UObjectDeleter *setDeleter(UObjectDeleter *d);
+    bool hasDeleter() {return deleter != nullptr;}
+
+    UElementsAreEqual *setComparer(UElementsAreEqual *c);
+
+    inline void* operator[](int32_t index) const {return elementAt(index);}
+
+    /**
+     * Removes the element at the given index from this vector and
+     * transfer ownership of it to the caller.  After this call, the
+     * caller owns the result and must delete it and the vector entry
+     * at 'index' is removed, shifting all subsequent entries back by
+     * one index and shortening the size of the vector by one.  If the
+     * index is out of range or if there is no item at the given index
+     * then 0 is returned and the vector is unchanged.
+     */
+    void* orphanElementAt(int32_t index);
+
+    /**
+     * Returns true if this vector contains none of the elements
+     * of the given vector.
+     * @param other vector to be checked for containment
+     * @return true if the test condition is met
+     */
+    UBool containsNone(const UVector& other) const;
+
+    /**
+     * Insert the given object into this vector at its sorted position
+     * as defined by 'compare'.  The current elements are assumed to
+     * be sorted already.
+     */
+    void sortedInsert(void* obj, UElementComparator *compare, UErrorCode& ec);
+
+    /**
+     * Insert the given integer into this vector at its sorted position
+     * as defined by 'compare'.  The current elements are assumed to
+     * be sorted already.
+     */
+    void sortedInsert(int32_t obj, UElementComparator *compare, UErrorCode& ec);
+
+    /**
+     * Sort the contents of the vector, assuming that the contents of the
+     * vector are of type int32_t.
+     */
+    void sorti(UErrorCode &ec);
+
+    /**
+      * Sort the contents of this vector, using a caller-supplied function
+      * to do the comparisons.  (It's confusing that
+      *  UVector's UElementComparator function is different from the
+      *  UComparator function type defined in uarrsort.h)
+      */
+    void sort(UElementComparator *compare, UErrorCode &ec);
+
+    /**
+     * Stable sort the contents of this vector using a caller-supplied function
+     * of type UComparator to do the comparison.  Provides more flexibility
+     * than UVector::sort() because an additional user parameter can be passed to
+     * the comparison function.
+     */
+    void sortWithUComparator(UComparator *compare, const void *context, UErrorCode &ec);
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for this class.
+     */
+    static UClassID U_EXPORT2 getStaticClassID();
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for the actual class.
+     */
+    virtual UClassID getDynamicClassID() const override;
+
+private:
+    int32_t indexOf(UElement key, int32_t startIndex = 0, int8_t hint = 0) const;
+
+    void sortedInsert(UElement e, UElementComparator *compare, UErrorCode& ec);
+
+public:
+    // Disallow
+    UVector(const UVector&) = delete;
+
+    // Disallow
+    UVector& operator=(const UVector&) = delete;
+
+};
+
+
+/**
+ * Ultralightweight C++ implementation of a `void*` stack
+ * that is (mostly) compatible with java.util.Stack.  As in java, this
+ * is merely a paper thin layer around UVector.  See the UVector
+ * documentation for further information.
+ *
+ * *Design notes*
+ *
+ * The element at index `n-1` is (of course) the top of the
+ * stack.
+ *
+ * The poorly named `empty()` method doesn't empty the
+ * stack; it determines if the stack is empty.
+ *
+ * @author Alan Liu
+ */
+class U_COMMON_API UStack : public UVector {
+public:
+    UStack(UErrorCode &status);
+
+    UStack(int32_t initialCapacity, UErrorCode &status);
+
+    UStack(UObjectDeleter *d, UElementsAreEqual *c, UErrorCode &status);
+
+    UStack(UObjectDeleter *d, UElementsAreEqual *c, int32_t initialCapacity, UErrorCode &status);
+
+    virtual ~UStack();
+
+    // It's okay not to have a virtual destructor (in UVector)
+    // because UStack has no special cleanup to do.
+
+    inline UBool empty() const {return isEmpty();}
+
+    inline void* peek() const {return lastElement();}
+
+    inline int32_t peeki() const {return lastElementi();}
+    
+    /**
+     * Pop and return an element from the stack.
+     * For stacks with a deleter function, the caller takes ownership
+     * of the popped element.
+     */
+    void* pop();
+    
+    int32_t popi();
+    
+    inline void* push(void* obj, UErrorCode &status) {
+        if (hasDeleter()) {
+            adoptElement(obj, status);
+            return (U_SUCCESS(status)) ? obj : nullptr;
+        } else {
+            addElement(obj, status);
+            return obj;
+        }
+    }
+
+    inline int32_t push(int32_t i, UErrorCode &status) {
+        addElement(i, status);
+        return i;
+    }
+
+    /*
+    If the object o occurs as an item in this stack,
+    this method returns the 1-based distance from the top of the stack.
+    */
+    int32_t search(void* obj) const;
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for this class.
+     */
+    static UClassID U_EXPORT2 getStaticClassID();
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for the actual class.
+     */
+    virtual UClassID getDynamicClassID() const override;
+
+    // Disallow
+    UStack(const UStack&) = delete;
+
+    // Disallow
+    UStack& operator=(const UStack&) = delete;
+};
+
+U_NAMESPACE_END
+
+#endif