Check in the pristine copy of ICU 51.2

icu51/source/common/uhash.h

Index: icu51/source/common/uhash.h
===================================================================
--- icu51/source/common/uhash.h	(revision 0)
+++ icu51/source/common/uhash.h	(revision 0)
@@ -0,0 +1,666 @@
+/*
+******************************************************************************
+*   Copyright (C) 1997-2011, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+******************************************************************************
+*   Date        Name        Description
+*   03/22/00    aliu        Adapted from original C++ ICU Hashtable.
+*   07/06/01    aliu        Modified to support int32_t keys on
+*                           platforms with sizeof(void*) < 32.
+******************************************************************************
+*/
+
+#ifndef UHASH_H
+#define UHASH_H
+
+#include "unicode/utypes.h"
+#include "cmemory.h"
+#include "uelement.h"
+
+/**
+ * UHashtable stores key-value pairs and does moderately fast lookup
+ * based on keys.  It provides a good tradeoff between access time and
+ * storage space.  As elements are added to it, it grows to accomodate
+ * them.  By default, the table never shrinks, even if all elements
+ * are removed from it.
+ *
+ * Keys and values are stored as void* pointers.  These void* pointers
+ * may be actual pointers to strings, objects, or any other structure
+ * in memory, or they may simply be integral values cast to void*.
+ * UHashtable doesn't care and manipulates them via user-supplied
+ * functions.  These functions hash keys, compare keys, delete keys,
+ * and delete values.  Some function pointers are optional (may be
+ * NULL); others must be supplied.  Several prebuilt functions exist
+ * to handle common key types.
+ *
+ * UHashtable ownership of keys and values is flexible, and controlled
+ * by whether or not the key deleter and value deleter functions are
+ * set.  If a void* key is actually a pointer to a deletable object,
+ * then UHashtable can be made to delete that object by setting the
+ * key deleter function pointer to a non-NULL value.  If this is done,
+ * then keys passed to uhash_put() are owned by the hashtable and will
+ * be deleted by it at some point, either as keys are replaced, or
+ * when uhash_close() is finally called.  The same is true of values
+ * and the value deleter function pointer.  Keys passed to methods
+ * other than uhash_put() are never owned by the hashtable.
+ *
+ * NULL values are not allowed.  uhash_get() returns NULL to indicate
+ * a key that is not in the table, and having a NULL value in the
+ * table would generate an ambiguous result.  If a key and a NULL
+ * value is passed to uhash_put(), this has the effect of doing a
+ * uhash_remove() on that key.  This keeps uhash_get(), uhash_count(),
+ * and uhash_nextElement() consistent with one another.
+ *
+ * To see everything in a hashtable, use uhash_nextElement() to
+ * iterate through its contents.  Each call to this function returns a
+ * UHashElement pointer.  A hash element contains a key, value, and
+ * hashcode.  During iteration an element may be deleted by calling
+ * uhash_removeElement(); iteration may safely continue thereafter.
+ * The uhash_remove() function may also be safely called in
+ * mid-iteration.  However, if uhash_put() is called during iteration
+ * then the iteration will be out of sync.  Under no circumstances
+ * should the UHashElement returned by uhash_nextElement be modified
+ * directly.
+ *
+ * By default, the hashtable grows when necessary, but never shrinks,
+ * even if all items are removed.  For most applications this is
+ * optimal.  However, in a highly dynamic usage where memory is at a
+ * premium, the table can be set to both grow and shrink by calling
+ * uhash_setResizePolicy() with the policy U_GROW_AND_SHRINK.  In a
+ * situation where memory is critical and the client wants a table
+ * that does not grow at all, the constant U_FIXED can be used.
+ */
+
+/********************************************************************
+ * Data Structures
+ ********************************************************************/
+
+U_CDECL_BEGIN
+
+/**
+ * A key or value within a UHashtable.
+ * The hashing and comparison functions take a pointer to a
+ * UHashTok, but the deleter receives the void* pointer within it.
+ */
+typedef UElement UHashTok;
+
+/**
+ * This is a single hash element.
+ */
+struct UHashElement {
+    /* Reorder these elements to pack nicely if necessary */
+    int32_t  hashcode;
+    UHashTok value;
+    UHashTok key;
+};
+typedef struct UHashElement UHashElement;
+
+/**
+ * A hashing function.
+ * @param key A key stored in a hashtable
+ * @return A NON-NEGATIVE hash code for parm.
+ */
+typedef int32_t U_CALLCONV UHashFunction(const UHashTok key);
+
+/**
+ * A key equality (boolean) comparison function.
+ */
+typedef UElementsAreEqual UKeyComparator;
+
+/**
+ * A value equality (boolean) comparison function.
+ */
+typedef UElementsAreEqual UValueComparator;
+
+/* see cmemory.h for UObjectDeleter and uprv_deleteUObject() */
+
+/**
+ * This specifies whether or not, and how, the hastable resizes itself.
+ * See uhash_setResizePolicy().
+ */
+enum UHashResizePolicy {
+    U_GROW,            /* Grow on demand, do not shrink */
+    U_GROW_AND_SHRINK, /* Grow and shrink on demand */
+    U_FIXED            /* Never change size */
+};
+
+/**
+ * The UHashtable struct.  Clients should treat this as an opaque data
+ * type and manipulate it only through the uhash_... API.
+ */
+struct UHashtable {
+
+    /* Main key-value pair storage array */
+
+    UHashElement *elements;
+
+    /* Function pointers */
+
+    UHashFunction *keyHasher;      /* Computes hash from key.
+                                   * Never null. */
+    UKeyComparator *keyComparator; /* Compares keys for equality.
+                                   * Never null. */
+    UValueComparator *valueComparator; /* Compares the values for equality */
+
+    UObjectDeleter *keyDeleter;    /* Deletes keys when required.
+                                   * If NULL won't do anything */
+    UObjectDeleter *valueDeleter;  /* Deletes values when required.
+                                   * If NULL won't do anything */
+
+    /* Size parameters */
+  
+    int32_t     count;      /* The number of key-value pairs in this table.
+                             * 0 <= count <= length.  In practice we
+                             * never let count == length (see code). */
+    int32_t     length;     /* The physical size of the arrays hashes, keys
+                             * and values.  Must be prime. */
+
+    /* Rehashing thresholds */
+    
+    int32_t     highWaterMark;  /* If count > highWaterMark, rehash */
+    int32_t     lowWaterMark;   /* If count < lowWaterMark, rehash */
+    float       highWaterRatio; /* 0..1; high water as a fraction of length */
+    float       lowWaterRatio;  /* 0..1; low water as a fraction of length */
+    
+    int8_t      primeIndex;     /* Index into our prime table for length.
+                                 * length == PRIMES[primeIndex] */
+    UBool       allocated; /* Was this UHashtable allocated? */
+};
+typedef struct UHashtable UHashtable;
+
+U_CDECL_END
+
+/********************************************************************
+ * API
+ ********************************************************************/
+
+/**
+ * Initialize a new UHashtable.
+ * @param keyHash A pointer to the key hashing function.  Must not be
+ * NULL.
+ * @param keyComp A pointer to the function that compares keys.  Must
+ * not be NULL.
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return A pointer to a UHashtable, or 0 if an error occurred.
+ * @see uhash_openSize
+ */
+U_CAPI UHashtable* U_EXPORT2 
+uhash_open(UHashFunction *keyHash,
+           UKeyComparator *keyComp,
+           UValueComparator *valueComp,
+           UErrorCode *status);
+
+/**
+ * Initialize a new UHashtable with a given initial size.
+ * @param keyHash A pointer to the key hashing function.  Must not be
+ * NULL.
+ * @param keyComp A pointer to the function that compares keys.  Must
+ * not be NULL.
+ * @param size The initial capacity of this hash table.
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return A pointer to a UHashtable, or 0 if an error occurred.
+ * @see uhash_open
+ */
+U_CAPI UHashtable* U_EXPORT2 
+uhash_openSize(UHashFunction *keyHash,
+               UKeyComparator *keyComp,
+               UValueComparator *valueComp,
+               int32_t size,
+               UErrorCode *status);
+
+/**
+ * Initialize an existing UHashtable.
+ * @param keyHash A pointer to the key hashing function.  Must not be
+ * NULL.
+ * @param keyComp A pointer to the function that compares keys.  Must
+ * not be NULL.
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return A pointer to a UHashtable, or 0 if an error occurred.
+ * @see uhash_openSize
+ */
+U_CAPI UHashtable* U_EXPORT2 
+uhash_init(UHashtable *hash,
+           UHashFunction *keyHash,
+           UKeyComparator *keyComp,
+           UValueComparator *valueComp,
+           UErrorCode *status);
+
+/**
+ * Close a UHashtable, releasing the memory used.
+ * @param hash The UHashtable to close. If hash is NULL no operation is performed.
+ */
+U_CAPI void U_EXPORT2 
+uhash_close(UHashtable *hash);
+
+
+
+/**
+ * Set the function used to hash keys.
+ * @param hash The UHashtable to set
+ * @param fn the function to be used hash keys; must not be NULL
+ * @return the previous key hasher; non-NULL
+ */
+U_CAPI UHashFunction *U_EXPORT2 
+uhash_setKeyHasher(UHashtable *hash, UHashFunction *fn);
+
+/**
+ * Set the function used to compare keys.  The default comparison is a
+ * void* pointer comparison.
+ * @param hash The UHashtable to set
+ * @param fn the function to be used compare keys; must not be NULL
+ * @return the previous key comparator; non-NULL
+ */
+U_CAPI UKeyComparator *U_EXPORT2 
+uhash_setKeyComparator(UHashtable *hash, UKeyComparator *fn);
+
+/**
+ * Set the function used to compare values.  The default comparison is a
+ * void* pointer comparison.
+ * @param hash The UHashtable to set
+ * @param fn the function to be used compare keys; must not be NULL
+ * @return the previous key comparator; non-NULL
+ */
+U_CAPI UValueComparator *U_EXPORT2 
+uhash_setValueComparator(UHashtable *hash, UValueComparator *fn);
+
+/**
+ * Set the function used to delete keys.  If this function pointer is
+ * NULL, this hashtable does not delete keys.  If it is non-NULL, this
+ * hashtable does delete keys.  This function should be set once
+ * before any elements are added to the hashtable and should not be
+ * changed thereafter.
+ * @param hash The UHashtable to set
+ * @param fn the function to be used delete keys, or NULL
+ * @return the previous key deleter; may be NULL
+ */
+U_CAPI UObjectDeleter *U_EXPORT2 
+uhash_setKeyDeleter(UHashtable *hash, UObjectDeleter *fn);
+
+/**
+ * Set the function used to delete values.  If this function pointer
+ * is NULL, this hashtable does not delete values.  If it is non-NULL,
+ * this hashtable does delete values.  This function should be set
+ * once before any elements are added to the hashtable and should not
+ * be changed thereafter.
+ * @param hash The UHashtable to set
+ * @param fn the function to be used delete values, or NULL
+ * @return the previous value deleter; may be NULL
+ */
+U_CAPI UObjectDeleter *U_EXPORT2 
+uhash_setValueDeleter(UHashtable *hash, UObjectDeleter *fn);
+
+/**
+ * Specify whether or not, and how, the hastable resizes itself.
+ * By default, tables grow but do not shrink (policy U_GROW).
+ * See enum UHashResizePolicy.
+ * @param hash The UHashtable to set
+ * @param policy The way the hashtable resizes itself, {U_GROW, U_GROW_AND_SHRINK, U_FIXED}
+ */
+U_CAPI void U_EXPORT2 
+uhash_setResizePolicy(UHashtable *hash, enum UHashResizePolicy policy);
+
+/**
+ * Get the number of key-value pairs stored in a UHashtable.
+ * @param hash The UHashtable to query.
+ * @return The number of key-value pairs stored in hash.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_count(const UHashtable *hash);
+
+/**
+ * Put a (key=pointer, value=pointer) item in a UHashtable.  If the
+ * keyDeleter is non-NULL, then the hashtable owns 'key' after this
+ * call.  If the valueDeleter is non-NULL, then the hashtable owns
+ * 'value' after this call.  Storing a NULL value is the same as
+ * calling uhash_remove().
+ * @param hash The target UHashtable.
+ * @param key The key to store.
+ * @param value The value to store, may be NULL (see above).
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return The previous value, or NULL if none.
+ * @see uhash_get
+ */
+U_CAPI void* U_EXPORT2 
+uhash_put(UHashtable *hash,
+          void *key,
+          void *value,
+          UErrorCode *status);
+
+/**
+ * Put a (key=integer, value=pointer) item in a UHashtable.
+ * keyDeleter must be NULL.  If the valueDeleter is non-NULL, then the
+ * hashtable owns 'value' after this call.  Storing a NULL value is
+ * the same as calling uhash_remove().
+ * @param hash The target UHashtable.
+ * @param key The integer key to store.
+ * @param value The value to store, may be NULL (see above).
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return The previous value, or NULL if none.
+ * @see uhash_get
+ */
+U_CAPI void* U_EXPORT2 
+uhash_iput(UHashtable *hash,
+           int32_t key,
+           void* value,
+           UErrorCode *status);
+
+/**
+ * Put a (key=pointer, value=integer) item in a UHashtable.  If the
+ * keyDeleter is non-NULL, then the hashtable owns 'key' after this
+ * call.  valueDeleter must be NULL.  Storing a 0 value is the same as
+ * calling uhash_remove().
+ * @param hash The target UHashtable.
+ * @param key The key to store.
+ * @param value The integer value to store.
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return The previous value, or 0 if none.
+ * @see uhash_get
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_puti(UHashtable *hash,
+           void* key,
+           int32_t value,
+           UErrorCode *status);
+
+/**
+ * Put a (key=integer, value=integer) item in a UHashtable.  If the
+ * keyDeleter is non-NULL, then the hashtable owns 'key' after this
+ * call.  valueDeleter must be NULL.  Storing a 0 value is the same as
+ * calling uhash_remove().
+ * @param hash The target UHashtable.
+ * @param key The key to store.
+ * @param value The integer value to store.
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return The previous value, or 0 if none.
+ * @see uhash_get
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_iputi(UHashtable *hash,
+           int32_t key,
+           int32_t value,
+           UErrorCode *status);
+
+/**
+ * Retrieve a pointer value from a UHashtable using a pointer key,
+ * as previously stored by uhash_put().
+ * @param hash The target UHashtable.
+ * @param key A pointer key stored in a hashtable
+ * @return The requested item, or NULL if not found.
+ */
+U_CAPI void* U_EXPORT2 
+uhash_get(const UHashtable *hash, 
+          const void *key);
+
+/**
+ * Retrieve a pointer value from a UHashtable using a integer key,
+ * as previously stored by uhash_iput().
+ * @param hash The target UHashtable.
+ * @param key An integer key stored in a hashtable
+ * @return The requested item, or NULL if not found.
+ */
+U_CAPI void* U_EXPORT2 
+uhash_iget(const UHashtable *hash,
+           int32_t key);
+
+/**
+ * Retrieve an integer value from a UHashtable using a pointer key,
+ * as previously stored by uhash_puti().
+ * @param hash The target UHashtable.
+ * @param key A pointer key stored in a hashtable
+ * @return The requested item, or 0 if not found.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_geti(const UHashtable *hash,
+           const void* key);
+/**
+ * Retrieve an integer value from a UHashtable using an integer key,
+ * as previously stored by uhash_iputi().
+ * @param hash The target UHashtable.
+ * @param key An integer key stored in a hashtable
+ * @return The requested item, or 0 if not found.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_igeti(const UHashtable *hash,
+           int32_t key);
+
+/**
+ * Remove an item from a UHashtable stored by uhash_put().
+ * @param hash The target UHashtable.
+ * @param key A key stored in a hashtable
+ * @return The item removed, or NULL if not found.
+ */
+U_CAPI void* U_EXPORT2 
+uhash_remove(UHashtable *hash,
+             const void *key);
+
+/**
+ * Remove an item from a UHashtable stored by uhash_iput().
+ * @param hash The target UHashtable.
+ * @param key An integer key stored in a hashtable
+ * @return The item removed, or NULL if not found.
+ */
+U_CAPI void* U_EXPORT2 
+uhash_iremove(UHashtable *hash,
+              int32_t key);
+
+/**
+ * Remove an item from a UHashtable stored by uhash_puti().
+ * @param hash The target UHashtable.
+ * @param key An key stored in a hashtable
+ * @return The item removed, or 0 if not found.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_removei(UHashtable *hash,
+              const void* key);
+
+/**
+ * Remove an item from a UHashtable stored by uhash_iputi().
+ * @param hash The target UHashtable.
+ * @param key An integer key stored in a hashtable
+ * @return The item removed, or 0 if not found.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_iremovei(UHashtable *hash,
+               int32_t key);
+
+/**
+ * Remove all items from a UHashtable.
+ * @param hash The target UHashtable.
+ */
+U_CAPI void U_EXPORT2 
+uhash_removeAll(UHashtable *hash);
+
+/**
+ * Locate an element of a UHashtable.  The caller must not modify the
+ * returned object.  The primary use of this function is to obtain the
+ * stored key when it may not be identical to the search key.  For
+ * example, if the compare function is a case-insensitive string
+ * compare, then the hash key may be desired in order to obtain the
+ * canonical case corresponding to a search key.
+ * @param hash The target UHashtable.
+ * @param key A key stored in a hashtable
+ * @return a hash element, or NULL if the key is not found.
+ */
+U_CAPI const UHashElement* U_EXPORT2 
+uhash_find(const UHashtable *hash, const void* key);
+
+/**
+ * Iterate through the elements of a UHashtable.  The caller must not
+ * modify the returned object.  However, uhash_removeElement() may be
+ * called during iteration to remove an element from the table.
+ * Iteration may safely be resumed afterwards.  If uhash_put() is
+ * called during iteration the iteration will then be out of sync and
+ * should be restarted.
+ * @param hash The target UHashtable.
+ * @param pos This should be set to -1 initially, and left untouched
+ * thereafter.
+ * @return a hash element, or NULL if no further key-value pairs
+ * exist in the table.
+ */
+U_CAPI const UHashElement* U_EXPORT2 
+uhash_nextElement(const UHashtable *hash,
+                  int32_t *pos);
+
+/**
+ * Remove an element, returned by uhash_nextElement(), from the table.
+ * Iteration may be safely continued afterwards.
+ * @param hash The hashtable
+ * @param e The element, returned by uhash_nextElement(), to remove.
+ * Must not be NULL.  Must not be an empty or deleted element (as long
+ * as this was returned by uhash_nextElement() it will not be empty or
+ * deleted).  Note: Although this parameter is const, it will be
+ * modified.
+ * @return the value that was removed.
+ */
+U_CAPI void* U_EXPORT2 
+uhash_removeElement(UHashtable *hash, const UHashElement* e);
+
+/********************************************************************
+ * UHashTok convenience
+ ********************************************************************/
+
+/**
+ * Return a UHashTok for an integer.
+ * @param i The given integer
+ * @return a UHashTok for an integer.
+ */
+/*U_CAPI UHashTok U_EXPORT2 
+uhash_toki(int32_t i);*/
+
+/**
+ * Return a UHashTok for a pointer.
+ * @param p The given pointer
+ * @return a UHashTok for a pointer.
+ */
+/*U_CAPI UHashTok U_EXPORT2 
+uhash_tokp(void* p);*/
+
+/********************************************************************
+ * UChar* and char* Support Functions
+ ********************************************************************/
+
+/**
+ * Generate a hash code for a null-terminated UChar* string.  If the
+ * string is not null-terminated do not use this function.  Use
+ * together with uhash_compareUChars.
+ * @param key The string (const UChar*) to hash.
+ * @return A hash code for the key.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_hashUChars(const UHashTok key);
+
+/**
+ * Generate a hash code for a null-terminated char* string.  If the
+ * string is not null-terminated do not use this function.  Use
+ * together with uhash_compareChars.
+ * @param key The string (const char*) to hash.
+ * @return A hash code for the key.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_hashChars(const UHashTok key);
+
+/**
+ * Generate a case-insensitive hash code for a null-terminated char*
+ * string.  If the string is not null-terminated do not use this
+ * function.  Use together with uhash_compareIChars.
+ * @param key The string (const char*) to hash.
+ * @return A hash code for the key.
+ */
+U_CAPI int32_t U_EXPORT2
+uhash_hashIChars(const UHashTok key);
+
+/**
+ * Comparator for null-terminated UChar* strings.  Use together with
+ * uhash_hashUChars.
+ * @param key1 The string for comparison
+ * @param key2 The string for comparison
+ * @return true if key1 and key2 are equal, return false otherwise.
+ */
+U_CAPI UBool U_EXPORT2 
+uhash_compareUChars(const UHashTok key1, const UHashTok key2);
+
+/**
+ * Comparator for null-terminated char* strings.  Use together with
+ * uhash_hashChars.
+ * @param key1 The string for comparison
+ * @param key2 The string for comparison
+ * @return true if key1 and key2 are equal, return false otherwise.
+ */
+U_CAPI UBool U_EXPORT2 
+uhash_compareChars(const UHashTok key1, const UHashTok key2);
+
+/**
+ * Case-insensitive comparator for null-terminated char* strings.  Use
+ * together with uhash_hashIChars.
+ * @param key1 The string for comparison
+ * @param key2 The string for comparison
+ * @return true if key1 and key2 are equal, return false otherwise.
+ */
+U_CAPI UBool U_EXPORT2 
+uhash_compareIChars(const UHashTok key1, const UHashTok key2);
+
+/********************************************************************
+ * UnicodeString Support Functions
+ ********************************************************************/
+
+/**
+ * Hash function for UnicodeString* keys.
+ * @param key The string (const char*) to hash.
+ * @return A hash code for the key.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_hashUnicodeString(const UElement key);
+
+/**
+ * Hash function for UnicodeString* keys (case insensitive).
+ * Make sure to use together with uhash_compareCaselessUnicodeString.
+ * @param key The string (const char*) to hash.
+ * @return A hash code for the key.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_hashCaselessUnicodeString(const UElement key);
+
+/********************************************************************
+ * int32_t Support Functions
+ ********************************************************************/
+
+/**
+ * Hash function for 32-bit integer keys.
+ * @param key The string (const char*) to hash.
+ * @return A hash code for the key.
+ */
+U_CAPI int32_t U_EXPORT2 
+uhash_hashLong(const UHashTok key);
+
+/**
+ * Comparator function for 32-bit integer keys.
+ * @param key1 The integer for comparison
+ * @param Key2 The integer for comparison
+ * @return true if key1 and key2 are equal, return false otherwise
+ */
+U_CAPI UBool U_EXPORT2 
+uhash_compareLong(const UHashTok key1, const UHashTok key2);
+
+/********************************************************************
+ * Other Support Functions
+ ********************************************************************/
+
+/**
+ * Deleter for Hashtable objects.
+ * @param obj The object to be deleted
+ */
+U_CAPI void U_EXPORT2 
+uhash_deleteHashtable(void *obj);
+
+/* Use uprv_free() itself as a deleter for any key or value allocated using uprv_malloc. */
+
+/**
+ * Checks if the given hash tables are equal or not.
+ * @param hash1
+ * @param hash2
+ * @return true if the hashtables are equal and false if not.
+ */
+U_CAPI UBool U_EXPORT2 
+uhash_equals(const UHashtable* hash1, const UHashtable* hash2);
+
+#endif
Property changes on: icu51/source/common/uhash.h
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Added: svn:eol-style
   + LF