'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
-'\" RCS: @(#) $Id: Hash.3,v 1.10.2.1 2003/07/18 16:56:24 dgp Exp $
-'\"
-'\" The definitions below are for supplemental macros used in Tcl/Tk
-'\" manual entries.
-'\"
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-'\"
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-'\"
-'\" .VE
-'\" End of vertical sidebar.
-'\"
-'\" .DS
-'\" Begin an indented unfilled display.
-'\"
-'\" .DE
-'\" End of indented unfilled display.
-'\"
-'\" .SO
-'\" Start of list of standard options for a Tk widget. The
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-'\" by tabs.
-'\"
-'\" .SE
-'\" End of list of standard options for a Tk widget.
-'\"
-'\" .OP cmdName dbName dbClass
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-'\"
-'\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
-'\"
-'\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
+.TH Tcl_Hash 3 "" Tcl "Tcl Library Procedures"
+.\" The -*- nroff -*- definitions below are for supplemental macros used
+.\" in Tcl/Tk manual entries.
+.\"
+.\" .AP type name in/out ?indent?
+.\" Start paragraph describing an argument to a library procedure.
+.\" type is type of argument (int, etc.), in/out is either "in", "out",
+.\" or "in/out" to describe whether procedure reads or modifies arg,
+.\" and indent is equivalent to second arg of .IP (shouldn't ever be
+.\" needed; use .AS below instead)
+.\"
+.\" .AS ?type? ?name?
+.\" Give maximum sizes of arguments for setting tab stops. Type and
+.\" name are examples of largest possible arguments that will be passed
+.\" to .AP later. If args are omitted, default tab stops are used.
+.\"
+.\" .BS
+.\" Start box enclosure. From here until next .BE, everything will be
+.\" enclosed in one large box.
+.\"
+.\" .BE
+.\" End of box enclosure.
+.\"
+.\" .CS
+.\" Begin code excerpt.
+.\"
+.\" .CE
+.\" End code excerpt.
+.\"
+.\" .VS ?version? ?br?
+.\" Begin vertical sidebar, for use in marking newly-changed parts
+.\" of man pages. The first argument is ignored and used for recording
+.\" the version when the .VS was added, so that the sidebars can be
+.\" found and removed when they reach a certain age. If another argument
+.\" is present, then a line break is forced before starting the sidebar.
+.\"
+.\" .VE
+.\" End of vertical sidebar.
+.\"
+.\" .DS
+.\" Begin an indented unfilled display.
+.\"
+.\" .DE
+.\" End of indented unfilled display.
+.\"
+.\" .SO ?manpage?
+.\" Start of list of standard options for a Tk widget. The manpage
+.\" argument defines where to look up the standard options; if
+.\" omitted, defaults to "options". The options follow on successive
+.\" lines, in three columns separated by tabs.
+.\"
+.\" .SE
+.\" End of list of standard options for a Tk widget.
+.\"
+.\" .OP cmdName dbName dbClass
+.\" Start of description of a specific option. cmdName gives the
+.\" option's name as specified in the class command, dbName gives
+.\" the option's name in the option database, and dbClass gives
+.\" the option's class in the option database.
+.\"
+.\" .UL arg1 arg2
+.\" Print arg1 underlined, then print arg2 normally.
+.\"
+.\" .QW arg1 ?arg2?
+.\" Print arg1 in quotes, then arg2 normally (for trailing punctuation).
+.\"
+.\" .PQ arg1 ?arg2?
+.\" Print an open parenthesis, arg1 in quotes, then arg2 normally
+.\" (for trailing punctuation) and then a closing parenthesis.
+.\"
+.\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
.if t .wh -1.3i ^B
.nr ^l \n(.l
.ad b
-'\" # Start an argument description
+.\" # Start an argument description
.de AP
.ie !"\\$4"" .TP \\$4
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.\}
.ta \\n()Au \\n()Bu
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.\".b
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..
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.if !"\\$1"" .nr )A \\w'\\$1'u+3n
.nr )C \\n()Bu+\\w'(in/out)'u+2n
..
.AS Tcl_Interp Tcl_CreateInterp in/out
-'\" # BS - start boxed text
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+.\" # ^b = 1
.de BS
.br
.mk ^y
.if n \l'\\n(.lu\(ul'
.if n .fi
..
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..
-'\" # VS - start vertical sidebar
-'\" # ^Y = starting y location
-'\" # ^v = 1 (for troff; for nroff this doesn't matter)
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+.\" # ^v = 1 (for troff; for nroff this doesn't matter)
.de VS
.if !"\\$2"" .br
.mk ^Y
.ie n 'mc \s12\(br\s0
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..
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+.\" # VE - end of vertical sidebar
.de VE
.ie n 'mc
.el \{\
.\}
.nr ^v 0
..
-'\" # Special macro to handle page bottom: finish off current
-'\" # box/sidebar if in box/sidebar mode, then invoked standard
-'\" # page bottom macro.
+.\" # Special macro to handle page bottom: finish off current
+.\" # box/sidebar if in box/sidebar mode, then invoked standard
+.\" # page bottom macro.
.de ^B
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'ti 0
.mk ^Y
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..
-'\" # DS - begin display
+.\" # DS - begin display
.de DS
.RS
.nf
.sp
..
-'\" # DE - end display
+.\" # DE - end display
.de DE
.fi
.RE
.sp
..
-'\" # SO - start of list of standard options
+.\" # SO - start of list of standard options
.de SO
+'ie '\\$1'' .ds So \\fBoptions\\fR
+'el .ds So \\fB\\$1\\fR
.SH "STANDARD OPTIONS"
.LP
.nf
.ta 5.5c 11c
.ft B
..
-'\" # SE - end of list of standard options
+.\" # SE - end of list of standard options
.de SE
.fi
.ft R
.LP
-See the \\fBoptions\\fR manual entry for details on the standard options.
+See the \\*(So manual entry for details on the standard options.
..
-'\" # OP - start of full description for a single option
+.\" # OP - start of full description for a single option
.de OP
.LP
.nf
.fi
.IP
..
-'\" # CS - begin code excerpt
+.\" # CS - begin code excerpt
.de CS
.RS
.nf
.ta .25i .5i .75i 1i
..
-'\" # CE - end code excerpt
+.\" # CE - end code excerpt
.de CE
.fi
.RE
..
+.\" # UL - underline word
.de UL
\\$1\l'|0\(ul'\\$2
..
-.TH Tcl_Hash 3 "" Tcl "Tcl Library Procedures"
+.\" # QW - apply quotation marks to word
+.de QW
+.ie '\\*(lq'"' ``\\$1''\\$2
+.\"" fix emacs highlighting
+.el \\*(lq\\$1\\*(rq\\$2
+..
+.\" # PQ - apply parens and quotation marks to word
+.de PQ
+.ie '\\*(lq'"' (``\\$1''\\$2)\\$3
+.\"" fix emacs highlighting
+.el (\\*(lq\\$1\\*(rq\\$2)\\$3
+..
+.\" # QR - quoted range
+.de QR
+.ie '\\*(lq'"' ``\\$1''\\-``\\$2''\\$3
+.\"" fix emacs highlighting
+.el \\*(lq\\$1\\*(rq\\-\\*(lq\\$2\\*(rq\\$3
+..
+.\" # MT - "empty" string
+.de MT
+.QW ""
+..
.BS
.SH NAME
Tcl_InitHashTable, Tcl_InitCustomHashTable, Tcl_InitObjHashTable, Tcl_DeleteHashTable, Tcl_CreateHashEntry, Tcl_DeleteHashEntry, Tcl_FindHashEntry, Tcl_GetHashValue, Tcl_SetHashValue, Tcl_GetHashKey, Tcl_FirstHashEntry, Tcl_NextHashEntry, Tcl_HashStats \- procedures to manage hash tables
.sp
\fBTcl_SetHashValue\fR(\fIentryPtr, value\fR)
.sp
-char *
+void *
\fBTcl_GetHashKey\fR(\fItablePtr, entryPtr\fR)
.sp
Tcl_HashEntry *
Tcl_HashEntry *
\fBTcl_NextHashEntry\fR(\fIsearchPtr\fR)
.sp
-CONST char *
+char *
\fBTcl_HashStats\fR(\fItablePtr\fR)
.SH ARGUMENTS
-.AS Tcl_HashSearch *searchPtr
+.AS "const Tcl_HashKeyType" *searchPtr out
.AP Tcl_HashTable *tablePtr in
Address of hash table structure (for all procedures but
\fBTcl_InitHashTable\fR, this must have been initialized by
previous call to \fBTcl_InitHashTable\fR).
.AP int keyType in
Kind of keys to use for new hash table. Must be either
-TCL_STRING_KEYS, TCL_ONE_WORD_KEYS, TCL_CUSTOM_TYPE_KEYS,
-TCL_CUSTOM_PTR_KEYS, or an integer value greater than 1.
+\fBTCL_STRING_KEYS\fR, \fBTCL_ONE_WORD_KEYS\fR, \fBTCL_CUSTOM_TYPE_KEYS\fR,
+\fBTCL_CUSTOM_PTR_KEYS\fR, or an integer value greater than 1.
.AP Tcl_HashKeyType *typePtr in
-Address of structure which defines the behaviour of the hash table.
-.AP "CONST char" *key in
+Address of structure which defines the behavior of the hash table.
+.AP "const void" *key in
Key to use for probe into table. Exact form depends on
\fIkeyType\fR used to create table.
.AP int *newPtr out
most one entry in a hash table with a particular key, but many entries
may have the same value. Keys can take one of four forms: strings,
one-word values, integer arrays, or custom keys defined by a
-Tcl_HashKeyType structure (See section \fBTHE TCL_HASHKEYTYPE
-STRUCTURE\fR below). All of the keys in a given table have the same
+Tcl_HashKeyType structure (See section \fBTHE TCL_HASHKEYTYPE STRUCTURE\fR
+below). All of the keys in a given table have the same
form, which is specified when the table is initialized.
.PP
The value of a hash table entry can be anything that fits in the same
-space as a ``char *'' pointer. Values for hash table entries are
+space as a
+.QW "char *"
+pointer. Values for hash table entries are
managed entirely by clients, not by the hash module itself. Typically
each entry's value is a pointer to a data structure managed by client
code.
first character of the string.
.IP \fBTCL_ONE_WORD_KEYS\fR 25
Keys are single-word values; they are passed to hashing routines
-and stored in hash table entries as ``char *'' values.
-The pointer value is the key; it need not (and usually doesn't)
+and stored in hash table entries as
+.QW "char *"
+values.
+The pointer value is the key; it need not (and usually does not)
actually point to a string.
.IP \fBTCL_CUSTOM_TYPE_KEYS\fR 25
Keys are of arbitrary type, and are stored in the entry. Hashing
.IP \fIother\fR 25
If \fIkeyType\fR is not one of the above,
then it must be an integer value greater than 1.
-In this case the keys will be arrays of ``int'' values, where
+In this case the keys will be arrays of
+.QW int
+values, where
\fIkeyType\fR gives the number of ints in each key.
This allows structures to be used as keys.
All keys must have the same size.
.PP
\fBTcl_CreateHashEntry\fR locates the entry corresponding to a
particular key, creating a new entry in the table if there
-wasn't already one with the given key.
+was not already one with the given key.
If an entry already existed with the given key then \fI*newPtr\fR
is set to zero.
If a new entry was created, then \fI*newPtr\fR is set to a non-zero
entry's value, such as freeing a structure that it points to.
.PP
\fBTcl_FindHashEntry\fR is similar to \fBTcl_CreateHashEntry\fR
-except that it doesn't create a new entry if the key doesn't exist;
+except that it does not create a new entry if the key doesn't exist;
instead, it returns NULL as result.
.PP
\fBTcl_GetHashValue\fR and \fBTcl_SetHashValue\fR are used to
read and write an entry's value, respectively.
-Values are stored and retrieved as type ``ClientData'', which is
+Values are stored and retrieved as type
+.QW ClientData ,
+which is
large enough to hold a pointer value. On almost all machines this is
large enough to hold an integer value too.
.PP
\fBTcl_GetHashKey\fR returns the key for a given hash table entry,
-either as a pointer to a string, a one-word (``char *'') key, or
+either as a pointer to a string, a one-word
+.PQ "char *"
+key, or
as a pointer to the first word of an array of integers, depending
on the \fIkeyType\fR used to create a hash table.
In all cases \fBTcl_GetHashKey\fR returns a result with type
-``char *''.
+.QW "char *" .
When the key is a string or array, the result of \fBTcl_GetHashKey\fR
points to information in the table entry; this information will
remain valid until the entry is deleted or its table is deleted.
.PP
\fBTcl_FirstHashEntry\fR and \fBTcl_NextHashEntry\fR may be used
to scan all of the entries in a hash table.
-A structure of type ``Tcl_HashSearch'', provided by the client,
+A structure of type
+.QW Tcl_HashSearch ,
+provided by the client,
is used to keep track of progress through the table.
\fBTcl_FirstHashEntry\fR initializes the search record and
returns the first entry in the table (or NULL if the table is
A call to \fBTcl_FirstHashEntry\fR followed by calls to
\fBTcl_NextHashEntry\fR will return each of the entries in
the table exactly once, in an arbitrary order.
-It is unadvisable to modify the structure of the table, e.g.
-by creating or deleting entries, while the search is in
-progress.
+It is inadvisable to modify the structure of the table, e.g.
+by creating or deleting entries, while the search is in progress,
+with the exception of deleting the entry returned by
+\fBTcl_FirstHashEntry\fR or \fBTcl_NextHashEntry\fR.
.PP
\fBTcl_HashStats\fR returns a dynamically-allocated string with
overall information about a hash table, such as the number of
use the procedures and macros defined here.
.SH "THE TCL_HASHKEYTYPE STRUCTURE"
.PP
-Extension writers can define new hash key types by defining four
-procedures, initializing a Tcl_HashKeyType structure to describe
-the type, and calling \fBTcl_InitCustomHashTable\fR.
-The \fBTcl_HashKeyType\fR structure is defined as follows:
+Extension writers can define new hash key types by defining four procedures,
+initializing a \fBTcl_HashKeyType\fR structure to describe the type, and
+calling \fBTcl_InitCustomHashTable\fR. The \fBTcl_HashKeyType\fR structure is
+defined as follows:
+.PP
.CS
typedef struct Tcl_HashKeyType {
int \fIversion\fR;
Tcl_CompareHashKeysProc *\fIcompareKeysProc\fR;
Tcl_AllocHashEntryProc *\fIallocEntryProc\fR;
Tcl_FreeHashEntryProc *\fIfreeEntryProc\fR;
-} Tcl_HashKeyType;
+} \fBTcl_HashKeyType\fR;
.CE
.PP
-The \fIversion\fR member is the version of the table. If this
-structure is extended in future then the version can be used
-to distinguish between different structures. It should be set
-to \fBTCL_HASH_KEY_TYPE_VERSION\fR.
+The \fIversion\fR member is the version of the table. If this structure is
+extended in future then the version can be used to distinguish between
+different structures. It should be set to \fBTCL_HASH_KEY_TYPE_VERSION\fR.
.PP
-The \fIflags\fR member is one or more of the following values OR'ed together:
+The \fIflags\fR member is 0 or one or more of the following values OR'ed
+together:
.IP \fBTCL_HASH_KEY_RANDOMIZE_HASH\fR 25
-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.
+There are some things, pointers for example which do not 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 randomizing the bits and then using the upper N
+bits as the index into the table.
+.IP \fBTCL_HASH_KEY_SYSTEM_HASH\fR 25
+This flag forces Tcl to use the memory allocation procedures provided by the
+operating system when allocating and freeing memory used to store the hash
+table data structures, and not any of Tcl's own customized memory allocation
+routines. This is important if the hash table is to be used in the
+implementation of a custom set of allocation routines, or something that a
+custom set of allocation routines might depend on, in order to avoid any
+circular dependency.
+.PP
+The \fIhashKeyProc\fR member contains the address of a function called to
+calculate a hash value for the key.
.PP
-The \fIhashKeyProc\fR member contains the address of a function
-called to calculate a hash value for the key.
.CS
-typedef unsigned int (Tcl_HashKeyProc) (
- Tcl_HashTable *\fItablePtr\fR,
- VOID *\fIkeyPtr\fR);
+typedef unsigned int \fBTcl_HashKeyProc\fR(
+ Tcl_HashTable *\fItablePtr\fR,
+ void *\fIkeyPtr\fR);
.CE
-If this is NULL then \fIkeyPtr\fR is used and
+.PP
+If this is NULL then \fIkeyPtr\fR is used and
\fBTCL_HASH_KEY_RANDOMIZE_HASH\fR is assumed.
.PP
-The \fIcompareKeysProc\fR member contains the address of a function
-called to compare two keys.
+The \fIcompareKeysProc\fR member contains the address of a function called to
+compare two keys.
+.PP
.CS
-typedef int (Tcl_CompareHashKeysProc) (VOID *\fIkeyPtr\fR,
- Tcl_HashEntry *\fIhPtr\fR);
+typedef int \fBTcl_CompareHashKeysProc\fR(
+ void *\fIkeyPtr\fR,
+ Tcl_HashEntry *\fIhPtr\fR);
.CE
-If this is NULL then the \fIkeyPtr\fR pointers are compared.
-If the keys don't match then the function returns 0, otherwise
-it returns 1.
.PP
-The \fIallocEntryProc\fR member contains the address of a function
-called to allocate space for an entry and initialise the key.
+If this is NULL then the \fIkeyPtr\fR pointers are compared. If the keys do
+not match then the function returns 0, otherwise it returns 1.
+.PP
+The \fIallocEntryProc\fR member contains the address of a function called to
+allocate space for an entry and initialize the key and clientData.
+.PP
.CS
-typedef Tcl_HashEntry *(Tcl_AllocHashEntryProc) (
- Tcl_HashTable *\fItablePtr\fR, VOID *\fIkeyPtr\fR);
+typedef Tcl_HashEntry *\fBTcl_AllocHashEntryProc\fR(
+ Tcl_HashTable *\fItablePtr\fR,
+ void *\fIkeyPtr\fR);
.CE
-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.
-String keys and array keys use this function to allocate enough
-space for the entry and the key in one block, rather than doing
-it in two blocks. This saves space for a pointer to the key from
-the entry and another memory allocation. Tcl_Obj * keys use this
-function to allocate enough space for an entry and increment the
-reference count on the object.
-If
-.PP
-The \fIfreeEntryProc\fR member contains the address of a function
-called to free space for an entry.
+.PP
+If this is NULL then \fBTcl_Alloc\fR is used to allocate enough space for a
+Tcl_HashEntry, the key pointer is assigned to key.oneWordValue and the
+clientData is set to NULL. String keys and array keys use this function to
+allocate enough space for the entry and the key in one block, rather than
+doing it in two blocks. This saves space for a pointer to the key from the
+entry and another memory allocation. Tcl_Obj* keys use this function to
+allocate enough space for an entry and increment the reference count on the
+value.
+.PP
+The \fIfreeEntryProc\fR member contains the address of a function called to
+free space for an entry.
+.PP
.CS
-typedef void (Tcl_FreeHashEntryProc) (Tcl_HashEntry *\fIhPtr\fR);
+typedef void \fBTcl_FreeHashEntryProc\fR(
+ Tcl_HashEntry *\fIhPtr\fR);
.CE
-If this is NULL then Tcl_Free is used to free the space for the
-entry. Tcl_Obj * keys use this function to decrement the
-reference count on the object.
+.PP
+If this is NULL then \fBTcl_Free\fR is used to free the space for the entry.
+Tcl_Obj* keys use this function to decrement the reference count on the
+value.
.SH KEYWORDS
hash table, key, lookup, search, value
OSDN Git Service
