GlobalSymTable.patch

   1 Subject: Use a hashtable for the global symbols
   2
   3 ---
   4
   5  source/interpret.c |  137 +++++++++++++++++++++++++++++++++++++----------------
   6  source/interpret.h |    1
   7  source/interpret.c |  133 ++++++++++++++++++++++++++++++++++++++---------------
   8  source/interpret.h |    1
   9  2 files changed, 97 insertions(+), 37 deletions(-)
  10
  11 diff --quilt old/source/interpret.c new/source/interpret.c
  12 --- old/source/interpret.c
  13 +++ new/source/interpret.c
  14 @@ -95,7 +95,10 @@ static int callSubroutineFromSymbol(Symb
  15  static int concatenateNwithSep(int nVals, const char *sep, char **result,
  16          int leaveParams);
  17  static int makeArrayKeyFromArgs(int nArgs, char **keyString, int leaveParams);
  18 -static void freeSymbolTable(Symbol *symTab);
  19 +static void freeSymbolList(Symbol *symList);
  20 +static void addToGlobalSymTab(Symbol *sym);
  21 +static unsigned int hashNameWith(unsigned int hash, const char *name);
  22 +static unsigned int hashName(const char *name);
  23  static int errCheck(const char *s);
  24  static int execError(const char *s1, const char *s2);
  25  static rbTreeNode *arrayEmptyAllocator(void);
  26 @@ -138,8 +141,11 @@ static void stackdumpInternal(int n, int
  27  #define DISASM_RT(i, n)
  28  #endif /* #ifndef DEBUG_STACK */
  29
  30 -/* Global symbols and function definitions */
  31 -static Symbol *GlobalSymList = NULL;
  32 +/* Global symbols and function definitions, is null initialized */
  33 +#define GLOBAL_SYMTAB_SHIFT 8
  34 +#define GLOBAL_SYMTAB_SIZE (1u << (GLOBAL_SYMTAB_SHIFT))
  35 +#define GLOBAL_SYMTAB_MASK ((GLOBAL_SYMTAB_SIZE) - 1)
  36 +static Symbol *GlobalSymTab[GLOBAL_SYMTAB_SIZE];
  37
  38  /* List of all memory allocated for strings */
  39  static char *AllocatedStrings = NULL;
  40 @@ -315,7 +321,7 @@ Program *FinishCreatingProgram(Accumulat
  41  void FreeProgram(Program *prog)
  42  {
  43      if (--prog->refcount == 0) {
  44 -        freeSymbolTable(prog->localSymList);
  45 +        freeSymbolList(prog->localSymList);
  46          XtFree((char *)prog->code);
  47          XtFree((char *)prog);
  48      }
  49 @@ -760,14 +766,14 @@ Symbol *InstallMultiAssignExpr(void)
  50  ** install an array iteration symbol
  51  ** it is tagged as an integer but holds an array node pointer
  52  */
  53 -#define ARRAY_ITER_SYM_PREFIX "aryiter "
  54 +#define ARRAY_ITER_SYM_PREFIX "aryiter #"
  55  Symbol *InstallIteratorSymbol(void)
  56  {
  57      char symbolName[sizeof(ARRAY_ITER_SYM_PREFIX) + TYPE_INT_STR_SIZE(int)];
  58      DataValue value;
  59 -    static int interatorNameIndex = 0;
  60 +    static int interatorNameIndex;
  61
  62 -    sprintf(symbolName, ARRAY_ITER_SYM_PREFIX "#%d", interatorNameIndex);
  63 +    sprintf(symbolName, ARRAY_ITER_SYM_PREFIX "%d", interatorNameIndex);
  64      ++interatorNameIndex;
  65      value.tag = INT_TAG;
  66      value.val.arrayPtr = NULL;
  67 @@ -780,50 +786,76 @@ Symbol *InstallIteratorSymbol(void)
  68  */
  69  Symbol *LookupStringConstSymbol(const char *value)
  70  {
  71 +    unsigned int idx;
  72      Symbol *s;
  73
  74 -    for (s = GlobalSymList; s != NULL; s = s->next) {
  75 -        if (s->type == CONST_SYM &&
  76 -            s->value.tag == STRING_TAG &&
  77 -            !strcmp(s->value.val.str.rep, value)) {
  78 -            return(s);
  79 +    for (idx = 0; idx < GLOBAL_SYMTAB_SIZE; idx++) {
  80 +        for (s = GlobalSymTab[idx]; s != NULL; s = s->next) {
  81 +            if (s->type == CONST_SYM
  82 +                    && s->value.tag == STRING_TAG
  83 +                    && !strcmp(s->value.val.str.rep, value)) {
  84 +                return(s);
  85 +            }
  86          }
  87      }
  88 +
  89      return(NULL);
  90  }
  91
  92  /*
  93  ** install string str in the global symbol table with a string name
  94  */
  95 +#define STRING_CONST_SYM_PREFIX "string #"
  96  Symbol *InstallStringConstSymbol(const char *str)
  97  {
  98 -    static int stringConstIndex = 0;
  99 -    char stringName[35];
 100 +    static int stringConstIndex;
 101 +    char stringName[sizeof(STRING_CONST_SYM_PREFIX) + TYPE_INT_STR_SIZE(int)];
 102      DataValue value;
 103 +
 104      Symbol *sym = LookupStringConstSymbol(str);
 105      if (sym) {
 106          return sym;
 107      }
 108
 109 -    sprintf(stringName, "string #%d", stringConstIndex++);
 110 +    sprintf(stringName, STRING_CONST_SYM_PREFIX "%d", stringConstIndex++);
 111      value.tag = STRING_TAG;
 112      AllocNStringCpy(&value.val.str, str);
 113      return(InstallSymbol(stringName, CONST_SYM, value));
 114  }
 115
 116 +static Symbol *lookupSymbol(const Symbol *symlist, const char *name,
 117 +        unsigned int hash)
 118 +{
 119 +    while (NULL != symlist) {
 120 +        if (hash == symlist->hash && strcmp(symlist->name, name) == 0)
 121 +            return symlist;
 122 +        symlist = symlist->next;
 123 +    }
 124 +
 125 +    return NULL;
 126 +}
 127 +
 128  /*
 129  ** find a symbol in the symbol table
 130  */
 131  Symbol *LookupSymbol(const char *name)
 132  {
 133 +    unsigned int hash;
 134      Symbol *s;
 135
 136 -    for (s = LocalSymList; s != NULL; s = s->next)
 137 -       if (strcmp(s->name, name) == 0)
 138 -           return s;
 139 -    for (s = GlobalSymList; s != NULL; s = s->next)
 140 -       if (strcmp(s->name, name) == 0)
 141 -           return s;
 142 +    /* calculate hash for name */
 143 +    hash = hashName(name);
 144 +
 145 +    /* search in local symbols */
 146 +    s = lookupSymbol(LocalSymList, name, hash);
 147 +    if (NULL != s)
 148 +        return s;
 149 +
 150 +    /* search in global symbols */
 151 +    s = lookupSymbol(GlobalSymTab[hash & GLOBAL_SYMTAB_MASK], name, hash);
 152 +    if (NULL != s)
 153 +        return s;
 154 +
 155      return NULL;
 156  }
 157
 158 @@ -840,12 +872,12 @@ Symbol *InstallSymbol(const char *name,
 159      s->type = type;
 160      s->value = value;
 161      s->added = 0;
 162 +    s->hash = hashName(s->name);
 163      if (type == LOCAL_SYM) {
 164         s->next = LocalSymList;
 165         LocalSymList = s;
 166      } else {
 167 -       s->next = GlobalSymList;
 168 -       GlobalSymList = s;
 169 +        addToGlobalSymTab(s);
 170      }
 171      return s;
 172  }
 173 @@ -909,8 +941,7 @@ Symbol *PromoteToGlobal(Symbol *sym)
 174         but this symbol has no program attached and ProgramFree() is not NULL
 175         pointer safe */
 176      sym->type = GLOBAL_SYM;
 177 -    sym->next = GlobalSymList;
 178 -    GlobalSymList = sym;
 179 +    addToGlobalSymTab(sym);
 180
 181      return sym;
 182  }
 183 @@ -1133,6 +1164,7 @@ void GarbageCollectStrings(void)
 184      SparseArrayEntryWrapper *nextAP, *thisAP;
 185      char *p, *next;
 186      Symbol *s;
 187 +    unsigned int idx;
 188
 189      /* mark all strings as unreferenced */
 190      for (p = AllocatedStrings; p != NULL; p = *((char **)p)) {
 191 @@ -1146,15 +1178,17 @@ void GarbageCollectStrings(void)
 192
 193      /* Sweep the global symbol list, marking which strings are still
 194         referenced */
 195 -    for (s = GlobalSymList; s != NULL; s = s->next) {
 196 -       if (s->value.tag == STRING_TAG) {
 197 -            /* test first because it may be read-only static string */
 198 -            if (!(*(s->value.val.str.rep - 1))) {
 199 -               *(s->value.val.str.rep - 1) = 1;
 200 +    for (idx = 0; idx < GLOBAL_SYMTAB_SIZE; idx++) {
 201 +        for (s = GlobalSymTab[idx]; s != NULL; s = s->next) {
 202 +            if (s->value.tag == STRING_TAG) {
 203 +                /* test first because it may be read-only static string */
 204 +                if (!(*(s->value.val.str.rep - 1))) {
 205 +                    *(s->value.val.str.rep - 1) = 1;
 206 +                }
 207 +            }
 208 +            else if (s->value.tag == ARRAY_TAG) {
 209 +                MarkArrayContentsAsUsed(s->value.val.arrayPtr);
 210              }
 211 -        }
 212 -        else if (s->value.tag == ARRAY_TAG) {
 213 -            MarkArrayContentsAsUsed(s->value.val.arrayPtr);
 214          }
 215      }
 216
 217 @@ -1221,17 +1255,42 @@ static void restoreContext(RestartData *
 218      FocusWindow = context->focusWindow;
 219  }
 220
 221 -static void freeSymbolTable(Symbol *symTab)
 222 +static void freeSymbolList(Symbol *symList)
 223  {
 224      Symbol *s;
 225
 226 -    while(symTab != NULL) {
 227 -        s = symTab;
 228 -        symTab = s->next;
 229 +    while (symList != NULL) {
 230 +        s = symList;
 231 +        symList = s->next;
 232          free(s);
 233      }
 234  }
 235
 236 +static unsigned int hashNameWith(unsigned int hash, const char *name)
 237 +{
 238 +    while (*name) {
 239 +        unsigned int c = *name++;
 240 +        hash = (hash * 16777619u) + c;
 241 +    }
 242 +
 243 +    return hash;
 244 +}
 245 +
 246 +static unsigned int hashName(const char *name)
 247 +{
 248 +    return hashNameWith(2166136261u, name);
 249 +}
 250 +
 251 +static void addToGlobalSymTab(Symbol *sym)
 252 +{
 253 +    unsigned int idx;
 254 +
 255 +    idx = sym->hash & GLOBAL_SYMTAB_MASK;
 256 +
 257 +    sym->next = GlobalSymTab[idx];
 258 +    GlobalSymTab[idx] = sym;
 259 +}
 260 +
 261  /* true, if you can pop n values */
 262  #define OK_TO_POP(n) \
 263      ((StackP - (n)) >= TheStack)
 264 diff --quilt old/source/interpret.h new/source/interpret.h
 265 --- old/source/interpret.h
 266 +++ new/source/interpret.h
 267 @@ -101,6 +101,7 @@ typedef struct SymbolRec {
 268      enum symTypes type;
 269      DataValue value;
 270      int added;
 271 +    unsigned int hash;
 272      struct SymbolRec *next;     /* to link to another */
 273      char name[1];
 274  } Symbol;