Move library tree where it belongs

lib-src/libnyquist/nyquist/cmt/hashrout.h

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+/* hashrout.h -- Rubine's hash table package */
+/* Copyright 1989 Carnegie Mellon University */
+
+/* ChangeLog:
+ *    2-jan-85 rbd    Added option to count entries: define COUNTER and
+ *          HASHENTER routine will increment it on new entries
+ *   28-Apr-03 DM     Explicit declaration of int type for HASHENTER() 
+ */
+
+/*
+ * Generic symbol table functions
+ *
+ * After writing this code over for a bunch of interpreters
+ * I think I know how to do it once and for all, generally
+ * enough for most application.
+ * There are enough settable parameters to suit anyone, and
+ * the defaults usually do something sane.
+ *
+ * The basic idea is that you have a bunch of symbol table entries
+ * that need to be entered or looked up given a character string.
+ * Symbol table entries are usually structures, and one element
+ * of the structure must be the character string of the key.
+ * The structure should be given a type name, and these routines
+ * are informed of the type name via
+ *    #define    HASHTYPE    type-name-of-symbol-table-entry
+ * You must inform the routines how to access the character string
+ * given the symbol table entry; for example
+ *    #define HASHELEM(p)    ((p).name)
+ * There are two size parameters - the number of different hash
+ * values and the number of symbol table entries to allocate at one
+ * time.  Both default to 256.
+ *    #define    HASHVAL        128
+ *    #define    HASHENTRIES    512
+ * The name of the function that performs both entry and lookup is
+ * enter(name) - it takes one argument, a character string.  The name
+ * of the function may be changed via
+ *    #define HASHENTER    new-name-for-enter-routine
+ * Note that if there is no entry in the table for name, name is entered
+ * automatically.  The returned structure will have only the name
+ * field filled in; the rest of the fields are guarenteed to be zero
+ * so an application can check if this is the first time name was entered.
+ * If HASHPOINT is defined, the enter routine returns a pointer to a hash
+ * table entry.  In the default case, i.e. HASHPOINT undefined, the
+ * enter routine returns an integer between zero and HASHENTRIES.
+ * The macro HASHENTRY(i) will, given that integer, return the
+ * table element (not a pointer to it), so for example,
+ *    HASHENTRY(enter(x)).name == x.
+ * Any file that wishes to use HASHENTRY should have at the top
+ *    #define    HASHTYPE    type-name-of-symbol-table-entry
+ *    #include "hash.h" 
+ * Note in this case at most HASHENTRIES entries will be allocated
+ * before hash table overflow.  If HASHPOINT is defined, allocations
+ * will take place until memory runs out.
+ * By default, hash strings are copied into space obtained from malloc
+ * before being placed in new entry.  This copying can be supressed
+ * by defining HASHNOCOPY.
+ * The following is an example of using the hash table stuff.
+
+typedef struct {
+    char    *n_name;
+    int    n_value;
+} symbolentry;
+
+#define    HASHTYPE    symbolentry
+#define HASHELEM(p)    ((p).n_name)
+#define HASHENTRIES    1024
+
+#include "hashrout.h"
+
+*/
+
+
+/*
+ * OK, now the meat.
+ */
+
+#ifndef    HASHTYPE
+#    include    "-- HASHTYPE undefined"
+#endif
+
+#ifndef    HASHELEM
+#    include    "-- HASHELEM undefined"
+#endif
+
+#ifndef    HASHVAL
+#    define    HASHVAL    256
+#endif
+
+#ifndef    HASHENTRIES
+#    define    HASHENTRIES    256
+#endif
+
+#ifndef    HASHENTER
+#    define    HASHENTER    enter
+#endif
+
+/*
+ * HASHNOCOPY, HASHPOINT are undefined by default
+ */
+
+/*
+ * get definition of hash elem structure
+ */
+
+#ifndef HASHENTRY
+#    include    "hash.h"
+#endif
+
+/*
+ * Table of pointers, indexed by hash values
+ */
+
+hashelem    *hashtab[HASHVAL];
+
+/*
+ * First chunk of elements, pointer to the start,
+ * and index for allocation
+ */
+
+hashelem    hashfirstchunk[HASHENTRIES];
+hashelem    *hashchunk = hashfirstchunk;
+int     hashindex = 0;
+
+/*
+ * stdio.h if we don't have it yet
+ */
+
+#ifndef _NFILE
+#    include <stdio.h>
+#endif
+
+/*
+ * Declare counter if necessary
+ */
+
+#ifdef COUNTER
+extern COUNTER;
+#endif
+
+/*
+ * The enter routine
+ */
+
+#ifdef HASHPOINT
+HASHTYPE *
+#else
+int
+#endif
+HASHENTER (s)
+char *s;
+{
+    register int i, hash;
+    register hashelem *elem;
+
+    /*
+     * Compute s's hash value
+     * I really should look up some good hash functions, but
+     * I haven't bothered.
+     */
+
+for(i = 0, hash = 0; s[i] != '\0' && i < 15; i++)
+    hash += (i + 1) * s[i];
+hash %= HASHVAL;
+
+/*
+      * search for s in the table
+     */
+
+for(elem = hashtab[hash]; elem != NULL; elem = elem->h_next)
+    if(strcmp(s, HASHELEM((elem->h_elem))) == 0) {    /* found it */
+#ifdef HASHPOINT
+        return(&elem->h_elem);
+#else
+        return(elem - hashfirstchunk);
+#endif
+    }
+
+if(hashindex >= HASHENTRIES) {
+#ifdef HASHPOINT
+    char *calloc();
+
+    hashindex = 0;
+    hashchunk = (hashelem *) calloc(HASHENTRIES, sizeof(hashelem));
+    if(hashchunk == NULL) {
+        gprintf(FATAL, "No mem for hash symbol table\n");
+        EXIT(1);
+#ifdef COUNTER
+        COUNTER++; /* optional symbol counter */
+#endif
+    }
+#else
+    gprintf(FATAL, "No hash table space, increase HASHENTRIES\n");
+    EXIT(1);
+#endif
+}
+
+/*
+      * Splice a new entry into the list and fill in the string field
+     */
+
+elem = &hashchunk[hashindex++];
+elem->h_next = hashtab[hash];
+hashtab[hash] = elem;
+
+#ifdef HASHNOCOPY
+HASHELEM((elem->h_elem)) = s;
+#else
+{
+    char *strcpy();
+    HASHELEM((elem->h_elem)) = memget((strlen(s) + 1));
+    strcpy(HASHELEM((elem->h_elem)), s);
+}
+#endif
+
+#ifdef HASHPOINT
+return(&elem->h_elem);
+#else
+return(elem - hashfirstchunk);
+#endif
+}