Conf: Replace keyword and symbol hash table with generic hash table.

The old hash table had fixed size, which makes it slow for config files
with large number of symbols and symbol lookups. The new one is growing
according to needs.

3 files changed, 78 insertions, 104 deletions

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index e9e385a6..620c119c 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -48,6 +48,7 @@
 #include "conf/conf.h"
 #include "conf/cf-parse.tab.h"
 #include "lib/string.h"
+#include "lib/hash.h"
 
 struct keyword {
   byte *name;
@@ -57,21 +58,31 @@ struct keyword {
 
 #include "conf/keywords.h"
 
-#define KW_HASH_SIZE 64
-static struct keyword *kw_hash[KW_HASH_SIZE];
-static int kw_hash_inited;
 
-#define SYM_HASH_SIZE 128
+static uint cf_hash(byte *c);
 
-struct sym_scope {
-  struct sym_scope *next;		/* Next on scope stack */
-  struct symbol *name;			/* Name of this scope */
-  int active;				/* Currently entered */
-};
-static struct sym_scope *conf_this_scope;
+#define KW_KEY(n)		n->name
+#define KW_NEXT(n)		n->next
+#define KW_EQ(a,b)		!strcmp(a,b)
+#define KW_FN(k)		cf_hash(k)
+#define KW_ORDER		8 /* Fixed */
+
+#define SYM_KEY(n)		n->name, n->scope->active
+#define SYM_NEXT(n)		n->next
+#define SYM_EQ(a,s1,b,s2)	!strcmp(a,b) && s1 == s2
+#define SYM_FN(k,s)		cf_hash(k)
+#define SYM_ORDER		6 /* Initial */
+
+#define SYM_REHASH		sym_rehash
+#define SYM_PARAMS		/8, *1, 2, 2, 6, 20
+
+
+HASH_DEFINE_REHASH_FN(SYM, struct symbol)
+
+HASH(struct keyword) kw_hash;
 
-static int cf_hash(byte *c);
-static inline struct symbol * cf_get_sym(byte *c, uint h0);
+
+static struct sym_scope *conf_this_scope;
 
 linpool *cfg_mem;
 
@@ -179,23 +190,20 @@ else: {
     yytext[yyleng-1] = 0;
     yytext++;
   }
-  unsigned int h = cf_hash(yytext);
-  struct keyword *k = kw_hash[h & (KW_HASH_SIZE-1)];
-  while (k)
+
+  struct keyword *k = HASH_FIND(kw_hash, KW, yytext);
+  if (k)
+  {
+    if (k->value > 0)
+      return k->value;
+    else
     {
-      if (!strcmp(k->name, yytext))
-	{
-	  if (k->value > 0)
-	    return k->value;
-	  else
-	    {
-	      cf_lval.i = -k->value;
-	      return ENUM;
-	    }
-	}
-      k=k->next;
+      cf_lval.i = -k->value;
+      return ENUM;
     }
-  cf_lval.s = cf_get_sym(yytext, h);
+  }
+
+  cf_lval.s = cf_get_symbol(yytext);
   return SYM;
 }
 
@@ -257,13 +265,13 @@ else: {
 
 %%
 
-static int
+static uint
 cf_hash(byte *c)
 {
-  unsigned int h = 13;
+  uint h = 13 << 24;
 
   while (*c)
-    h = (h * 37) + *c++;
+    h = h + (h >> 2) + (h >> 5) + ((uint) *c++ << 24);
   return h;
 }
 
@@ -428,56 +436,27 @@ check_eof(void)
 }
 
 static struct symbol *
-cf_new_sym(byte *c, uint h0)
+cf_new_symbol(byte *c)
 {
-  uint h = h0 & (SYM_HASH_SIZE-1);
-  struct symbol *s, **ht;
-  int l;
-
-  if (!new_config->sym_hash)
-    new_config->sym_hash = cfg_allocz(SYM_HASH_SIZE * sizeof(struct keyword *));
-  ht = new_config->sym_hash;
-  l = strlen(c);
+  struct symbol *s;
+
+  uint l = strlen(c);
   if (l > SYM_MAX_LEN)
     cf_error("Symbol too long");
+
   s = cfg_alloc(sizeof(struct symbol) + l);
-  s->next = ht[h];
-  ht[h] = s;
   s->scope = conf_this_scope;
   s->class = SYM_VOID;
   s->def = NULL;
   s->aux = 0;
   strcpy(s->name, c);
-  return s;
-}
 
-static struct symbol *
-cf_find_sym(struct config *cfg, byte *c, uint h0)
-{
-  uint h = h0 & (SYM_HASH_SIZE-1);
-  struct symbol *s, **ht;
+  if (!new_config->sym_hash.data)
+    HASH_INIT(new_config->sym_hash, new_config->pool, SYM_ORDER);
 
-  if (ht = cfg->sym_hash)
-    {
-      for(s = ht[h]; s; s=s->next)
-	if (!strcmp(s->name, c) && s->scope->active)
-	  return s;
-    }
-  if (ht = cfg->sym_fallback)
-    {
-      /* We know only top-level scope is active */
-      for(s = ht[h]; s; s=s->next)
-	if (!strcmp(s->name, c) && s->scope->active)
-	  return s;
-    }
-
-  return NULL;
-}
+  HASH_INSERT2(new_config->sym_hash, SYM, new_config->pool, s);
 
-static inline struct symbol *
-cf_get_sym(byte *c, uint h0)
-{
-  return cf_find_sym(new_config, c, h0) ?: cf_new_sym(c, h0);
+  return s;
 }
 
 /**
@@ -494,7 +473,18 @@ cf_get_sym(byte *c, uint h0)
 struct symbol *
 cf_find_symbol(struct config *cfg, byte *c)
 {
-  return cf_find_sym(cfg, c, cf_hash(c));
+  struct symbol *s;
+
+  if (cfg->sym_hash.data &&
+      (s = HASH_FIND(cfg->sym_hash, SYM, c, 1)))
+    return s;
+
+  if (cfg->fallback &&
+      cfg->fallback->sym_hash.data &&
+      (s = HASH_FIND(cfg->fallback->sym_hash, SYM, c, 1)))
+    return s;
+
+  return NULL;
 }
 
 /**
@@ -509,7 +499,7 @@ cf_find_symbol(struct config *cfg, byte *c)
 struct symbol *
 cf_get_symbol(byte *c)
 {
-  return cf_get_sym(c, cf_hash(c));
+  return cf_find_symbol(new_config, c) ?: cf_new_symbol(c);
 }
 
 struct symbol *
@@ -522,7 +512,7 @@ cf_default_name(char *template, int *counter)
   for(;;)
     {
       bsprintf(buf, template, ++(*counter));
-      s = cf_get_sym(buf, cf_hash(buf));
+      s = cf_get_symbol(buf);
       if (s->class == SYM_VOID)
 	return s;
       if (!perc)
@@ -553,7 +543,7 @@ cf_define_symbol(struct symbol *sym, int type, void *def)
     {
       if (sym->scope == conf_this_scope)
 	cf_error("Symbol already defined");
-      sym = cf_new_sym(sym->name, cf_hash(sym->name));
+      sym = cf_new_symbol(sym->name);
     }
   sym->class = type;
   sym->def = def;
@@ -563,15 +553,11 @@ cf_define_symbol(struct symbol *sym, int type, void *def)
 static void
 cf_lex_init_kh(void)
 {
-  struct keyword *k;
+  HASH_INIT(kw_hash, &root_pool, KW_ORDER);
 
-  for(k=keyword_list; k->name; k++)
-    {
-      unsigned h = cf_hash(k->name) & (KW_HASH_SIZE-1);
-      k->next = kw_hash[h];
-      kw_hash[h] = k;
-    }
-  kw_hash_inited = 1;
+  struct keyword *k;
+  for (k=keyword_list; k->name; k++)
+    HASH_INSERT(kw_hash, KW, k);
 }
 
 /**
@@ -585,7 +571,7 @@ cf_lex_init_kh(void)
 void
 cf_lex_init(int is_cli, struct config *c)
 {
-  if (!kw_hash_inited)
+  if (!kw_hash.data)
     cf_lex_init_kh();
 
   ifs_head = ifs = push_ifs(NULL);
@@ -644,24 +630,6 @@ cf_pop_scope(void)
   ASSERT(conf_this_scope);
 }
 
-struct symbol *
-cf_walk_symbols(struct config *cf, struct symbol *sym, int *pos)
-{
-  for(;;)
-    {
-      if (!sym)
-	{
-	  if (*pos >= SYM_HASH_SIZE)
-	    return NULL;
-	  sym = cf->sym_hash[(*pos)++];
-	}
-      else
-	sym = sym->next;
-      if (sym && sym->scope->active)
-	return sym;
-    }
-}
-
 /**
  * cf_symbol_class_name - get name of a symbol class
  * @sym: symbol
diff --git a/conf/conf.c b/conf/conf.c
index 0a4e3f8c..7f4eb7e8 100644
--- a/conf/conf.c
+++ b/conf/conf.c
@@ -163,7 +163,7 @@ int
 cli_parse(struct config *c)
 {
   int done = 0;
-  c->sym_fallback = config->sym_hash;
+  c->fallback = config;
   new_config = c;
   cfg_mem = c->mem;
   if (setjmp(conf_jmpbuf))
@@ -174,7 +174,7 @@ cli_parse(struct config *c)
   done = 1;
 
 cleanup:
-  c->sym_fallback = NULL;
+  c->fallback = NULL;
   new_config = NULL;
   cfg_mem = NULL;
   return done;
diff --git a/conf/conf.h b/conf/conf.h
index 41cb434f..bf74b76b 100644
--- a/conf/conf.h
+++ b/conf/conf.h
@@ -11,6 +11,7 @@
 
 #include "lib/resource.h"
 #include "lib/timer.h"
+#include "lib/hash.h"
 
 
 /* Configuration structure */
@@ -50,8 +51,8 @@ struct config {
   char *err_file_name;			/* File name containing error */
   char *file_name;			/* Name of main configuration file */
   int file_fd;				/* File descriptor of main configuration file */
-  struct symbol **sym_hash;		/* Lexer: symbol hash table */
-  struct symbol **sym_fallback;		/* Lexer: fallback symbol hash table */
+  HASH(struct symbol) sym_hash;		/* Lexer: symbol hash table */
+  struct config *fallback;		/* Link to regular config for CLI parsing */
   int obstacle_count;			/* Number of items blocking freeing of this config */
   int shutdown;				/* This is a pseudo-config for daemon shutdown */
   bird_clock_t load_time;		/* When we've got this configuration */
@@ -112,6 +113,12 @@ struct symbol {
   char name[1];
 };
 
+struct sym_scope {
+  struct sym_scope *next;		/* Next on scope stack */
+  struct symbol *name;			/* Name of this scope */
+  int active;				/* Currently entered */
+};
+
 #define SYM_MAX_LEN 64
 
 /* Remember to update cf_symbol_class_name() */
@@ -154,7 +161,6 @@ struct symbol *cf_default_name(char *template, int *counter);
 struct symbol *cf_define_symbol(struct symbol *symbol, int type, void *def);
 void cf_push_scope(struct symbol *);
 void cf_pop_scope(void);
-struct symbol *cf_walk_symbols(struct config *cf, struct symbol *sym, int *pos);
 char *cf_symbol_class_name(struct symbol *sym);
 
 static inline int cf_symbol_is_constant(struct symbol *sym)