Check in the pristine copy of ICU 4.6...

icu46/source/common/cmemory.h

+/*
+******************************************************************************
+*
+*   Copyright (C) 1997-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+******************************************************************************
+*
+* File CMEMORY.H
+*
+*  Contains stdlib.h/string.h memory functions
+*
+* @author       Bertrand A. Damiba
+*
+* Modification History:
+*
+*   Date        Name        Description
+*   6/20/98     Bertrand    Created.
+*  05/03/99     stephen     Changed from functions to macros.
+*
+******************************************************************************
+*/
+
+#ifndef CMEMORY_H
+#define CMEMORY_H
+
+#include <stddef.h>
+#include <string.h>
+#include "unicode/utypes.h"
+#include "unicode/localpointer.h"
+
+#define uprv_memcpy(dst, src, size) U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size)
+#define uprv_memmove(dst, src, size) U_STANDARD_CPP_NAMESPACE memmove(dst, src, size)
+#define uprv_memset(buffer, mark, size) U_STANDARD_CPP_NAMESPACE memset(buffer, mark, size)
+#define uprv_memcmp(buffer1, buffer2, size) U_STANDARD_CPP_NAMESPACE memcmp(buffer1, buffer2,size)
+
+U_CAPI void * U_EXPORT2
+uprv_malloc(size_t s);
+
+U_CAPI void * U_EXPORT2
+uprv_realloc(void *mem, size_t size);
+
+U_CAPI void U_EXPORT2
+uprv_free(void *mem);
+
+/**
+ * This should align the memory properly on any machine.
+ * This is very useful for the safeClone functions.
+ */
+typedef union {
+    long    t1;
+    double  t2;
+    void   *t3;
+} UAlignedMemory;
+
+/**
+ * Get the least significant bits of a pointer (a memory address).
+ * For example, with a mask of 3, the macro gets the 2 least significant bits,
+ * which will be 0 if the pointer is 32-bit (4-byte) aligned.
+ *
+ * ptrdiff_t is the most appropriate integer type to cast to.
+ * size_t should work too, since on most (or all?) platforms it has the same
+ * width as ptrdiff_t.
+ */
+#define U_POINTER_MASK_LSB(ptr, mask) (((ptrdiff_t)(char *)(ptr)) & (mask))
+
+/**
+ * Get the amount of bytes that a pointer is off by from
+ * the previous UAlignedMemory-aligned pointer.
+ */
+#define U_ALIGNMENT_OFFSET(ptr) U_POINTER_MASK_LSB(ptr, sizeof(UAlignedMemory) - 1)
+
+/**
+ * Get the amount of bytes to add to a pointer
+ * in order to get the next UAlignedMemory-aligned address.
+ */
+#define U_ALIGNMENT_OFFSET_UP(ptr) (sizeof(UAlignedMemory) - U_ALIGNMENT_OFFSET(ptr))
+
+/**
+  *  Indicate whether the ICU allocation functions have been used.
+  *  This is used to determine whether ICU is in an initial, unused state.
+  */
+U_CFUNC UBool 
+cmemory_inUse(void);
+
+/**
+  *  Heap clean up function, called from u_cleanup()
+  *    Clears any user heap functions from u_setMemoryFunctions()
+  *    Does NOT deallocate any remaining allocated memory.
+  */
+U_CFUNC UBool 
+cmemory_cleanup(void);
+
+#ifdef XP_CPLUSPLUS
+
+U_NAMESPACE_BEGIN
+
+/**
+ * "Smart pointer" class, deletes memory via uprv_free().
+ * For most methods see the LocalPointerBase base class.
+ * Adds operator[] for array item access.
+ *
+ * @see LocalPointerBase
+ */
+template<typename T>
+class LocalMemory : public LocalPointerBase<T> {
+public:
+    /**
+     * Constructor takes ownership.
+     * @param p simple pointer to an array of T items that is adopted
+     */
+    explicit LocalMemory(T *p=NULL) : LocalPointerBase<T>(p) {}
+    /**
+     * Destructor deletes the memory it owns.
+     */
+    ~LocalMemory() {
+        uprv_free(LocalPointerBase<T>::ptr);
+    }
+    /**
+     * Deletes the array it owns,
+     * and adopts (takes ownership of) the one passed in.
+     * @param p simple pointer to an array of T items that is adopted
+     */
+    void adoptInstead(T *p) {
+        uprv_free(LocalPointerBase<T>::ptr);
+        LocalPointerBase<T>::ptr=p;
+    }
+    /**
+     * Deletes the array it owns, allocates a new one and reset its bytes to 0.
+     * Returns the new array pointer.
+     * If the allocation fails, then the current array is unchanged and
+     * this method returns NULL.
+     * @param newCapacity must be >0
+     * @return the allocated array pointer, or NULL if the allocation failed
+     */
+    inline T *allocateInsteadAndReset(int32_t newCapacity=1);
+    /**
+     * Deletes the array it owns and allocates a new one, copying length T items.
+     * Returns the new array pointer.
+     * If the allocation fails, then the current array is unchanged and
+     * this method returns NULL.
+     * @param newCapacity must be >0
+     * @param length number of T items to be copied from the old array to the new one;
+     *               must be no more than the capacity of the old array,
+     *               which the caller must track because the LocalMemory does not track it
+     * @return the allocated array pointer, or NULL if the allocation failed
+     */
+    inline T *allocateInsteadAndCopy(int32_t newCapacity=1, int32_t length=0);
+    /**
+     * Array item access (writable).
+     * No index bounds check.
+     * @param i array index
+     * @return reference to the array item
+     */
+    T &operator[](ptrdiff_t i) const { return LocalPointerBase<T>::ptr[i]; }
+};
+
+template<typename T>
+inline T *LocalMemory<T>::allocateInsteadAndReset(int32_t newCapacity) {
+    if(newCapacity>0) {
+        T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
+        if(p!=NULL) {
+            uprv_memset(p, 0, newCapacity*sizeof(T));
+            uprv_free(LocalPointerBase<T>::ptr);
+            LocalPointerBase<T>::ptr=p;
+        }
+        return p;
+    } else {
+        return NULL;
+    }
+}
+
+
+template<typename T>
+inline T *LocalMemory<T>::allocateInsteadAndCopy(int32_t newCapacity, int32_t length) {
+    if(newCapacity>0) {
+        T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
+        if(p!=NULL) {
+            if(length>0) {
+                if(length>newCapacity) {
+                    length=newCapacity;
+                }
+                uprv_memcpy(p, LocalPointerBase<T>::ptr, length*sizeof(T));
+            }
+            uprv_free(LocalPointerBase<T>::ptr);
+            LocalPointerBase<T>::ptr=p;
+        }
+        return p;
+    } else {
+        return NULL;
+    }
+}
+
+/**
+ * Simple array/buffer management class using uprv_malloc() and uprv_free().
+ * Provides an internal array with fixed capacity. Can alias another array
+ * or allocate one.
+ *
+ * The array address is properly aligned for type T. It might not be properly
+ * aligned for types larger than T (or larger than the largest subtype of T).
+ *
+ * Unlike LocalMemory and LocalArray, this class never adopts
+ * (takes ownership of) another array.
+ */
+template<typename T, int32_t stackCapacity>
+class MaybeStackArray {
+public:
+    /**
+     * Default constructor initializes with internal T[stackCapacity] buffer.
+     */
+    MaybeStackArray() : ptr(stackArray), capacity(stackCapacity), needToRelease(FALSE) {}
+    /**
+     * Destructor deletes the array (if owned).
+     */
+    ~MaybeStackArray() { releaseArray(); }
+    /**
+     * Returns the array capacity (number of T items).
+     * @return array capacity
+     */
+    int32_t getCapacity() const { return capacity; }
+    /**
+     * Access without ownership change.
+     * @return the array pointer
+     */
+    T *getAlias() const { return ptr; }
+    /**
+     * Returns the array limit. Simple convenience method.
+     * @return getAlias()+getCapacity()
+     */
+    T *getArrayLimit() const { return getAlias()+capacity; }
+    /**
+     * Access without ownership change. Same as getAlias().
+     * A class instance can be used directly in expressions that take a T *.
+     * @return the array pointer
+     */
+    operator T *() const { return ptr; }
+    /**
+     * Array item access (writable).
+     * No index bounds check.
+     * @param i array index
+     * @return reference to the array item
+     */
+    T &operator[](ptrdiff_t i) { return ptr[i]; }
+    /**
+     * Deletes the array (if owned) and aliases another one, no transfer of ownership.
+     * If the arguments are illegal, then the current array is unchanged.
+     * @param otherArray must not be NULL
+     * @param otherCapacity must be >0
+     */
+    void aliasInstead(T *otherArray, int32_t otherCapacity) {
+        if(otherArray!=NULL && otherCapacity>0) {
+            releaseArray();
+            ptr=otherArray;
+            capacity=otherCapacity;
+            needToRelease=FALSE;
+        }
+    };
+    /**
+     * Deletes the array (if owned) and allocates a new one, copying length T items.
+     * Returns the new array pointer.
+     * If the allocation fails, then the current array is unchanged and
+     * this method returns NULL.
+     * @param newCapacity can be less than or greater than the current capacity;
+     *                    must be >0
+     * @param length number of T items to be copied from the old array to the new one
+     * @return the allocated array pointer, or NULL if the allocation failed
+     */
+    inline T *resize(int32_t newCapacity, int32_t length=0);
+    /**
+     * Gives up ownership of the array if owned, or else clones it,
+     * copying length T items; resets itself to the internal stack array.
+     * Returns NULL if the allocation failed.
+     * @param length number of T items to copy when cloning,
+     *        and capacity of the clone when cloning
+     * @param resultCapacity will be set to the returned array's capacity (output-only)
+     * @return the array pointer;
+     *         caller becomes responsible for deleting the array
+     * @draft ICU 4.4
+     */
+    inline T *orphanOrClone(int32_t length, int32_t &resultCapacity);
+private:
+    T *ptr;
+    int32_t capacity;
+    UBool needToRelease;
+    T stackArray[stackCapacity];
+    void releaseArray() {
+        if(needToRelease) {
+            uprv_free(ptr);
+        }
+    }
+    /* No comparison operators with other MaybeStackArray's. */
+    bool operator==(const MaybeStackArray & /*other*/) {return FALSE;};
+    bool operator!=(const MaybeStackArray & /*other*/) {return TRUE;};
+    /* No ownership transfer: No copy constructor, no assignment operator. */
+    MaybeStackArray(const MaybeStackArray & /*other*/) {};
+    void operator=(const MaybeStackArray & /*other*/) {};
+
+    // No heap allocation. Use only on the stack.
+    //   (Declaring these functions private triggers a cascade of problems:
+    //      MSVC insists on exporting an instantiation of MaybeStackArray, which
+    //      requires that all functions be defined.
+    //      An empty implementation of new() is rejected, it must return a value.
+    //      Returning NULL is rejected by gcc for operator new.
+    //      The expedient thing is just not to override operator new.
+    //      While relatively pointless, heap allocated instances will function.
+    // static void * U_EXPORT2 operator new(size_t size); 
+    // static void * U_EXPORT2 operator new[](size_t size);
+#if U_HAVE_PLACEMENT_NEW
+    // static void * U_EXPORT2 operator new(size_t, void *ptr);
+#endif
+};
+
+template<typename T, int32_t stackCapacity>
+inline T *MaybeStackArray<T, stackCapacity>::resize(int32_t newCapacity, int32_t length) {
+    if(newCapacity>0) {
+        T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
+        if(p!=NULL) {
+            if(length>0) {
+                if(length>capacity) {
+                    length=capacity;
+                }
+                if(length>newCapacity) {
+                    length=newCapacity;
+                }
+                uprv_memcpy(p, ptr, length*sizeof(T));
+            }
+            releaseArray();
+            ptr=p;
+            capacity=newCapacity;
+            needToRelease=TRUE;
+        }
+        return p;
+    } else {
+        return NULL;
+    }
+}
+
+template<typename T, int32_t stackCapacity>
+inline T *MaybeStackArray<T, stackCapacity>::orphanOrClone(int32_t length, int32_t &resultCapacity) {
+    T *p;
+    if(needToRelease) {
+        p=ptr;
+    } else if(length<=0) {
+        return NULL;
+    } else {
+        if(length>capacity) {
+            length=capacity;
+        }
+        p=(T *)uprv_malloc(length*sizeof(T));
+        if(p==NULL) {
+            return NULL;
+        }
+        uprv_memcpy(p, ptr, length*sizeof(T));
+    }
+    resultCapacity=length;
+    ptr=stackArray;
+    capacity=stackCapacity;
+    needToRelease=FALSE;
+    return p;
+}
+
+/**
+ * Variant of MaybeStackArray that allocates a header struct and an array
+ * in one contiguous memory block, using uprv_malloc() and uprv_free().
+ * Provides internal memory with fixed array capacity. Can alias another memory
+ * block or allocate one.
+ * The stackCapacity is the number of T items in the internal memory,
+ * not counting the H header.
+ * Unlike LocalMemory and LocalArray, this class never adopts
+ * (takes ownership of) another memory block.
+ */
+template<typename H, typename T, int32_t stackCapacity>
+class MaybeStackHeaderAndArray {
+public:
+    /**
+     * Default constructor initializes with internal H+T[stackCapacity] buffer.
+     */
+    MaybeStackHeaderAndArray() : ptr(&stackHeader), capacity(stackCapacity), needToRelease(FALSE) {}
+    /**
+     * Destructor deletes the memory (if owned).
+     */
+    ~MaybeStackHeaderAndArray() { releaseMemory(); }
+    /**
+     * Returns the array capacity (number of T items).
+     * @return array capacity
+     */
+    int32_t getCapacity() const { return capacity; }
+    /**
+     * Access without ownership change.
+     * @return the header pointer
+     */
+    H *getAlias() const { return ptr; }
+    /**
+     * Returns the array start.
+     * @return array start, same address as getAlias()+1
+     */
+    T *getArrayStart() const { return reinterpret_cast<T *>(getAlias()+1); }
+    /**
+     * Returns the array limit.
+     * @return array limit
+     */
+    T *getArrayLimit() const { return getArrayStart()+capacity; }
+    /**
+     * Access without ownership change. Same as getAlias().
+     * A class instance can be used directly in expressions that take a T *.
+     * @return the header pointer
+     */
+    operator H *() const { return ptr; }
+    /**
+     * Array item access (writable).
+     * No index bounds check.
+     * @param i array index
+     * @return reference to the array item
+     */
+    T &operator[](ptrdiff_t i) { return getArrayStart()[i]; }
+    /**
+     * Deletes the memory block (if owned) and aliases another one, no transfer of ownership.
+     * If the arguments are illegal, then the current memory is unchanged.
+     * @param otherArray must not be NULL
+     * @param otherCapacity must be >0
+     */
+    void aliasInstead(H *otherMemory, int32_t otherCapacity) {
+        if(otherMemory!=NULL && otherCapacity>0) {
+            releaseMemory();
+            ptr=otherMemory;
+            capacity=otherCapacity;
+            needToRelease=FALSE;
+        }
+    };
+    /**
+     * Deletes the memory block (if owned) and allocates a new one,
+     * copying the header and length T array items.
+     * Returns the new header pointer.
+     * If the allocation fails, then the current memory is unchanged and
+     * this method returns NULL.
+     * @param newCapacity can be less than or greater than the current capacity;
+     *                    must be >0
+     * @param length number of T items to be copied from the old array to the new one
+     * @return the allocated pointer, or NULL if the allocation failed
+     */
+    inline H *resize(int32_t newCapacity, int32_t length=0);
+    /**
+     * Gives up ownership of the memory if owned, or else clones it,
+     * copying the header and length T array items; resets itself to the internal memory.
+     * Returns NULL if the allocation failed.
+     * @param length number of T items to copy when cloning,
+     *        and array capacity of the clone when cloning
+     * @param resultCapacity will be set to the returned array's capacity (output-only)
+     * @return the header pointer;
+     *         caller becomes responsible for deleting the array
+     * @draft ICU 4.4
+     */
+    inline H *orphanOrClone(int32_t length, int32_t &resultCapacity);
+private:
+    H *ptr;
+    int32_t capacity;
+    UBool needToRelease;
+    // stackHeader must precede stackArray immediately.
+    H stackHeader;
+    T stackArray[stackCapacity];
+    void releaseMemory() {
+        if(needToRelease) {
+            uprv_free(ptr);
+        }
+    }
+    /* No comparison operators with other MaybeStackHeaderAndArray's. */
+    bool operator==(const MaybeStackHeaderAndArray & /*other*/) {return FALSE;};
+    bool operator!=(const MaybeStackHeaderAndArray & /*other*/) {return TRUE;};
+    /* No ownership transfer: No copy constructor, no assignment operator. */
+    MaybeStackHeaderAndArray(const MaybeStackHeaderAndArray & /*other*/) {};
+    void operator=(const MaybeStackHeaderAndArray & /*other*/) {};
+
+    // No heap allocation. Use only on the stack.
+    //   (Declaring these functions private triggers a cascade of problems;
+    //    see the MaybeStackArray class for details.)
+    // static void * U_EXPORT2 operator new(size_t size); 
+    // static void * U_EXPORT2 operator new[](size_t size);
+#if U_HAVE_PLACEMENT_NEW
+    // static void * U_EXPORT2 operator new(size_t, void *ptr);
+#endif
+};
+
+template<typename H, typename T, int32_t stackCapacity>
+inline H *MaybeStackHeaderAndArray<H, T, stackCapacity>::resize(int32_t newCapacity,
+                                                                int32_t length) {
+    if(newCapacity>=0) {
+        H *p=(H *)uprv_malloc(sizeof(H)+newCapacity*sizeof(T));
+        if(p!=NULL) {
+            if(length<0) {
+                length=0;
+            } else if(length>0) {
+                if(length>capacity) {
+                    length=capacity;
+                }
+                if(length>newCapacity) {
+                    length=newCapacity;
+                }
+            }
+            uprv_memcpy(p, ptr, sizeof(H)+length*sizeof(T));
+            releaseMemory();
+            ptr=p;
+            capacity=newCapacity;
+            needToRelease=TRUE;
+        }
+        return p;
+    } else {
+        return NULL;
+    }
+}
+
+template<typename H, typename T, int32_t stackCapacity>
+inline H *MaybeStackHeaderAndArray<H, T, stackCapacity>::orphanOrClone(int32_t length,
+                                                                       int32_t &resultCapacity) {
+    H *p;
+    if(needToRelease) {
+        p=ptr;
+    } else {
+        if(length<0) {
+            length=0;
+        } else if(length>capacity) {
+            length=capacity;
+        }
+        p=(H *)uprv_malloc(sizeof(H)+length*sizeof(T));
+        if(p==NULL) {
+            return NULL;
+        }
+        uprv_memcpy(p, ptr, sizeof(H)+length*sizeof(T));
+    }
+    resultCapacity=length;
+    ptr=&stackHeader;
+    capacity=stackCapacity;
+    needToRelease=FALSE;
+    return p;
+}
+
+U_NAMESPACE_END
+
+#endif  /* XP_CPLUSPLUS */
+#endif  /* CMEMORY_H */