diff options
Diffstat (limited to 'generic/tcl.h')
| -rw-r--r-- | generic/tcl.h | 184 |
1 files changed, 160 insertions, 24 deletions
diff --git a/generic/tcl.h b/generic/tcl.h index ed6c2ac..2add458 100644 --- a/generic/tcl.h +++ b/generic/tcl.h @@ -12,7 +12,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tcl.h,v 1.72 2000/06/24 00:26:08 ericm Exp $ + * RCS: @(#) $Id: tcl.h,v 1.73 2000/07/19 22:15:29 ericm Exp $ */ #ifndef _TCL @@ -337,6 +337,14 @@ typedef long LONG; #endif /* + * This flag controls whether binary compatability is maintained with + * extensions built against a previous version of Tcl. + */ +#ifndef TCL_PRESERVE_BINARY_COMPATABILITY +#define TCL_PRESERVE_BINARY_COMPATABILITY 1 +#endif + +/* * Data structures defined opaquely in this module. The definitions below * just provide dummy types. A few fields are made visible in Tcl_Interp * structures, namely those used for returning a string result from @@ -942,13 +950,30 @@ typedef struct Tcl_DString { #define TCL_LINK_READ_ONLY 0x80 /* - * Forward declaration of Tcl_HashTable. Needed by some C++ compilers - * to prevent errors when the forward reference to Tcl_HashTable is - * encountered in the Tcl_HashEntry structure. + * Forward declarations of Tcl_HashTable and related types. */ -#ifdef __cplusplus -struct Tcl_HashTable; +typedef struct Tcl_HashKeyType Tcl_HashKeyType; +typedef struct Tcl_HashTable Tcl_HashTable; +typedef struct Tcl_HashEntry Tcl_HashEntry; + +typedef unsigned int (Tcl_HashKeyProc) _ANSI_ARGS_((Tcl_HashTable *tablePtr, + VOID *keyPtr)); +typedef int (Tcl_CompareHashKeysProc) _ANSI_ARGS_((VOID *keyPtr, + Tcl_HashEntry *hPtr)); +typedef Tcl_HashEntry *(Tcl_AllocHashEntryProc) _ANSI_ARGS_(( + Tcl_HashTable *tablePtr, VOID *keyPtr)); +typedef void (Tcl_FreeHashEntryProc) _ANSI_ARGS_((Tcl_HashEntry *hPtr)); + +/* + * This flag controls whether the hash table stores the hash of a key, or + * recalculates it. There should be no reason for turning this flag off + * as it is completely binary and source compatible unless you directly + * access the bucketPtr member of the Tcl_HashTableEntry structure. This + * member has been removed and the space used to store the hash value. + */ +#ifndef TCL_HASH_KEY_STORE_HASH +#define TCL_HASH_KEY_STORE_HASH 1 #endif /* @@ -957,14 +982,25 @@ struct Tcl_HashTable; * defined below. */ -typedef struct Tcl_HashEntry { - struct Tcl_HashEntry *nextPtr; /* Pointer to next entry in this +struct Tcl_HashEntry { + Tcl_HashEntry *nextPtr; /* Pointer to next entry in this * hash bucket, or NULL for end of * chain. */ - struct Tcl_HashTable *tablePtr; /* Pointer to table containing entry. */ - struct Tcl_HashEntry **bucketPtr; /* Pointer to bucket that points to + Tcl_HashTable *tablePtr; /* Pointer to table containing entry. */ +#if TCL_HASH_KEY_STORE_HASH +# if TCL_PRESERVE_BINARY_COMPATABILITY + VOID *hash; /* Hash value, stored as pointer to + * ensure that the offsets of the + * fields in this structure are not + * changed. */ +# else + unsigned int hash; /* Hash value. */ +# endif +#else + Tcl_HashEntry **bucketPtr; /* Pointer to bucket that points to * first entry in this entry's chain: * used for deleting the entry. */ +#endif ClientData clientData; /* Application stores something here * with Tcl_SetHashValue. */ union { /* Key has one of these forms: */ @@ -978,16 +1014,72 @@ typedef struct Tcl_HashEntry { * will be as large as needed to hold * the key. */ } key; /* MUST BE LAST FIELD IN RECORD!! */ -} Tcl_HashEntry; +}; /* + * Flags used in Tcl_HashKeyType. + * + * TCL_HASH_KEY_RANDOMIZE_HASH: + * There are some things, pointers for example + * which don't hash well because they do not use + * the lower bits. If this flag is set then the + * hash table will attempt to rectify this by + * randomising the bits and then using the upper + * N bits as the index into the table. + */ +#define TCL_HASH_KEY_RANDOMIZE_HASH 0x1 + +/* + * Structure definition for the methods associated with a hash table + * key type. + */ +#define TCL_HASH_KEY_TYPE_VERSION 1 +struct Tcl_HashKeyType { + int version; /* Version of the table. If this structure is + * extended in future then the version can be + * used to distinguish between different + * structures. + */ + + int flags; /* Flags, see above for details. */ + + /* Calculates a hash value for the key. If this is NULL then the pointer + * itself is used as a hash value. + */ + Tcl_HashKeyProc *hashKeyProc; + + /* Compares two keys and returns zero if they do not match, and non-zero + * if they do. If this is NULL then the pointers are compared. + */ + Tcl_CompareHashKeysProc *compareKeysProc; + + /* Called to allocate memory for a new entry, i.e. if the key is a + * string then this could allocate a single block which contains enough + * space for both the entry and the string. Only the key field of the + * allocated Tcl_HashEntry structure needs to be filled in. If something + * else needs to be done to the key, i.e. incrementing a reference count + * then that should be done by this function. If this is NULL then Tcl_Alloc + * is used to allocate enough space for a Tcl_HashEntry and the key pointer + * is assigned to key.oneWordValue. + */ + Tcl_AllocHashEntryProc *allocEntryProc; + + /* Called to free memory associated with an entry. If something else needs + * to be done to the key, i.e. decrementing a reference count then that + * should be done by this function. If this is NULL then Tcl_Free is used + * to free the Tcl_HashEntry. + */ + Tcl_FreeHashEntryProc *freeEntryProc; +}; + +/* * Structure definition for a hash table. Must be in tcl.h so clients * can allocate space for these structures, but clients should never * access any fields in this structure. */ #define TCL_SMALL_HASH_TABLE 4 -typedef struct Tcl_HashTable { +struct Tcl_HashTable { Tcl_HashEntry **buckets; /* Pointer to bucket array. Each * element points to first entry in * bucket's hash chain, or NULL. */ @@ -1006,16 +1098,20 @@ typedef struct Tcl_HashTable { int mask; /* Mask value used in hashing * function. */ int keyType; /* Type of keys used in this table. - * It's either TCL_OBJ_KEYS, + * It's either TCL_CUSTOM_KEYS, * TCL_STRING_KEYS, TCL_ONE_WORD_KEYS, * or an integer giving the number of * ints that is the size of the key. */ - Tcl_HashEntry *(*findProc) _ANSI_ARGS_((struct Tcl_HashTable *tablePtr, +#if TCL_PRESERVE_BINARY_COMPATABILITY + Tcl_HashEntry *(*findProc) _ANSI_ARGS_((Tcl_HashTable *tablePtr, CONST char *key)); - Tcl_HashEntry *(*createProc) _ANSI_ARGS_((struct Tcl_HashTable *tablePtr, + Tcl_HashEntry *(*createProc) _ANSI_ARGS_((Tcl_HashTable *tablePtr, CONST char *key, int *newPtr)); -} Tcl_HashTable; +#endif + Tcl_HashKeyType *typePtr; /* Type of the keys used in the + * Tcl_HashTable. */ +}; /* * Structure definition for information used to keep track of searches @@ -1032,35 +1128,75 @@ typedef struct Tcl_HashSearch { /* * Acceptable key types for hash tables: + * + * TCL_STRING_KEYS: The keys are strings, they are copied into + * the entry. + * TCL_ONE_WORD_KEYS: The keys are pointers, the pointer is stored + * in the entry. + * TCL_CUSTOM_TYPE_KEYS: The keys are arbitrary types which are copied + * into the entry. + * TCL_CUSTOM_PTR_KEYS: The keys are pointers to arbitrary types, the + * pointer is stored in the entry. + * + * While maintaining binary compatability the above have to be distinct + * values as they are used to differentiate between old versions of the + * hash table which don't have a typePtr and new ones which do. Once binary + * compatability is discarded in favour of making more wide spread changes + * TCL_STRING_KEYS can be the same as TCL_CUSTOM_TYPE_KEYS, and + * TCL_ONE_WORD_KEYS can be the same as TCL_CUSTOM_PTR_KEYS because they + * simply determine how the key is accessed from the entry and not the + * behaviour. */ -#define TCL_OBJ_KEYS -1 #define TCL_STRING_KEYS 0 #define TCL_ONE_WORD_KEYS 1 +#if TCL_PRESERVE_BINARY_COMPATABILITY +# define TCL_CUSTOM_TYPE_KEYS -2 +# define TCL_CUSTOM_PTR_KEYS -1 +#else +# define TCL_CUSTOM_TYPE_KEYS TCL_STRING_KEYS +# define TCL_CUSTOM_PTR_KEYS TCL_ONE_WORD_KEYS +#endif + /* * Macros for clients to use to access fields of hash entries: */ #define Tcl_GetHashValue(h) ((h)->clientData) #define Tcl_SetHashValue(h, value) ((h)->clientData = (ClientData) (value)) -#define Tcl_GetHashKey(tablePtr, h) \ - ((char *) (((tablePtr)->keyType == TCL_ONE_WORD_KEYS || \ - (tablePtr)->keyType == TCL_OBJ_KEYS) \ - ? (h)->key.oneWordValue \ - : (h)->key.string)) +#if TCL_PRESERVE_BINARY_COMPATABILITY +# define Tcl_GetHashKey(tablePtr, h) \ + ((char *) (((tablePtr)->keyType == TCL_ONE_WORD_KEYS || \ + (tablePtr)->keyType == TCL_CUSTOM_PTR_KEYS) \ + ? (h)->key.oneWordValue \ + : (h)->key.string)) +#else +# define Tcl_GetHashKey(tablePtr, h) \ + ((char *) (((tablePtr)->keyType == TCL_ONE_WORD_KEYS) \ + ? (h)->key.oneWordValue \ + : (h)->key.string)) +#endif /* * Macros to use for clients to use to invoke find and create procedures * for hash tables: */ -#define Tcl_FindHashEntry(tablePtr, key) \ +#if TCL_PRESERVE_BINARY_COMPATABILITY +# define Tcl_FindHashEntry(tablePtr, key) \ (*((tablePtr)->findProc))(tablePtr, key) -#define Tcl_CreateHashEntry(tablePtr, key, newPtr) \ +# define Tcl_CreateHashEntry(tablePtr, key, newPtr) \ (*((tablePtr)->createProc))(tablePtr, key, newPtr) +#endif /* + * Macro to use new extended version of Tcl_InitHashTable. + */ +#define Tcl_InitHashTable(tablePtr, keyType) \ + Tcl_InitHashTableEx(tablePtr, keyType, NULL) + +/* * Flag values to pass to Tcl_DoOneEvent to disable searches * for some kinds of events: */ |