X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Fkmp.h;h=67889a17e9e78c03ce30e5eee9f39935ad0ffac4;hb=b5f9a4654516e0ec37373e198e6b3a6f6a2a186d;hp=d4836988dda500336fde89df4c03f80a1ac05e02;hpb=e1ccb1a25eae9368b00589d948cc0e23718f2fbb;p=libucw.git

diff --git a/lib/kmp.h b/lib/kmp.h
index d4836988..67889a17 100644
--- a/lib/kmp.h
+++ b/lib/kmp.h
@@ -14,34 +14,74 @@
  *  preprocessor macros, it generates KMP structures and functions
  *  with the parameters given.
  *
+ *  This file contains only construction of the automaton. The search
+ *  itself can be generated by inclusion of file lib/kmp-search.h.
+ *  Separeted headers allow the user to define multiple search
+ *  routines for one common set of key strings.
+ *
+ *  Example:
+ *
+ *	#define KMP_PREFIX(x) kmp_##x
+ *	#define KMP_WANT_CLEANUP
+ *	#define KMP_WANT_SEARCH // includes lib/kmp-search.h automatically
+ *	#define KMPS_FOUND(kmp,src,s) printf("found\n")
+ *	#include "lib/kmp.h"
+ *
+ *    [...]
+ *
+ *	struct kmp_struct kmp;	// a structure describing the whole automaton
+ *	kmp_init(&kmp);		// initialization (must be called before all other functions)
+ *
+ *	// add key strings we want to search
+ *	kmp_add(&kmp, "aaa");
+ *	kmp_add(&kmp, "abc");
+ *
+ *	// complete the automaton, no more strings can be added later
+ *	kmp_build(&kmp);
+ *
+ *	// example of search, should print single "found" to stdout
+ *	kmp_run(&kmp, "aabaabca");
+ *
+ *	// destroy all internal structures
+ *	kmp_cleanup(&kmp);
+ *
+ *
+ *  Brief description of all parameters:
  *
  *    Basic parameters:
  *     	KMP_PREFIX(x)		macro to add a name prefix (used on all global names
- *				defined by the KMP generator); mandatory
+ *				defined by the KMP generator); mandatory;
+ *				we abbreviate this to P(x) below
  *
  *	KMP_CHAR		alphabet type, the default is u16
- *	
- *	KMP_SOURCE		user-defined text source; KMP_GET_CHAR must 
- *	KMP_GET_CHAR(kmp,src,c)	return next character from the input or zero at the end;
+ *
+ *	KMP_SOURCE		user-defined text source; KMP_GET_CHAR must
+ *	KMP_GET_CHAR(kmp,src,c)	return zero at the end or nonzero together with the next character in c otherwise;
  *				if not defined, zero-terminated array of bytes is used as the input
- *	
- *	KMP_VARS		user-defined data in main structure (a structure describing
- *				the whole automaton)
- *	KMP_STATE_VARS		user-defined data in each state of the automaton
+ *
+ *	KMP_VARS		user-defined variables in 'struct P(struct)'
+ *				-- a structure describing the whole automaton;
+ *				these variables are stored in .u substructure to avoid collisions
+ *	KMP_STATE_VARS		user-defined variables in 'struct P(state)'
+ *				-- created for each state of the automaton;
+ *				these variables are stored in .u substructure to avoid collisions
  *
  *    Parameters which select how the input is interpreted (if KMP_SOURCE is unset):
  *	KMP_USE_ASCII		reads single bytes from the input (default)
  *	KMP_USE_UTF8		reads UTF-8 characters from the input (valid UTF-8 needed)
  *	KMP_TOLOWER		converts all to lowercase
  *	KMP_UNACCENT		removes accents
- *	KMP_ONLYALPHA		converts non-alphas to KMP_CONTROL_CHAR
- *	KMP_CONTROL_CHAR	special control character (default is ':')
+ *	KMP_ONLYALPHA		converts non-alphas to KMP_CONTROL_CHAR (see below)
  *
- *    Parameters controlling add():
- * 	KMP_ADD_EXTRA_ARGS	extra arguments
- * 	KMP_ADD_INIT(kmp,src)
- * 	KMP_ADD_NEW(kmp,src,s)
- * 	KMP_ADD_DUP(kmp,src,s)
+ *    Parameters controlling add(kmp, src):
+ * 	KMP_ADD_EXTRA_ARGS	extra arguments, should be used carefully because of possible collisions
+ * 	KMP_ADD_INIT(kmp,src)	called in the beginning of add(), src is the first
+ *      KMP_INIT_STATE(kmp,s)   initialization of a new state s (called before KMP_ADD_{NEW,DUP});
+ *      			null state is not included and should be handled after init() if necessary;
+ *      			all user-defined data are filled by zeros before call to KMP_INIT_STATE
+ * 	KMP_ADD_NEW(kmp,src,s)	initialize last state of every new key string (called after KMP_INIT_STATE);
+ * 				the string must be parsed before so src is after the last string's character
+ * 	KMP_ADD_DUP(kmp,src,s)  analogy of KMP_ADD_NEW called for duplicates
  *
  *    Parameters to build():
  *      KMP_BUILD_STATE(kmp,s)	called for all states (including null) in order of non-decreasing tree depth
@@ -49,13 +89,19 @@
  *    Other parameters:
  *	KMP_WANT_CLEANUP	define cleanup()
  *	KMP_WANT_SEARCH		includes lib/kmp-search.h with the same prefix;
- *				there can be multiple search variants for a single KMP structure
- *
+ *				there can be multiple search variants for a single KMP automaton
  *	KMP_USE_POOL		allocates in a given pool
- *
- *	KMP_GIVE_ALLOC
- *	KMP_GIVE_HASHFN
- *	KMP_GIVE_EQ
+ *	KMP_CONTROL_CHAR	special control character (default is ':')
+ *	KMP_GIVE_ALLOC		if set, you must supply custom allocation functions:
+ *				void *alloc(unsigned int size) -- allocate space for
+ *				a state. Default is pooled allocation from a local pool or HASH_USE_POOL.
+ *				void free(void *) -- the converse.
+ *	KMP_GIVE_HASHFN		if set, you must supply custom hash function:
+ *				unsigned int hash(struct P(struct) *kmp, struct P(state) *state, KMP_CHAR c);
+ *				default hash function works only for integer character types
+ *	KMP_GIVE_EQ		if set, you must supply custom compare function of two characters:
+ *				int eq(struct P(struct) *kmp, KMP_CHAR a, KMP_CHAR b);
+ *				default is 'a == b'
  */
 
 #ifndef KMP_PREFIX
@@ -85,15 +131,15 @@ typedef struct {} P(node_t);
 struct P(struct);
 
 struct P(state) {
-  struct P(state) *from;	/* state with previous character */
-  struct P(state) *back;	/* backwards edge to the largest shorter state */
-  struct P(state) *next;	/* largest shorter match */
-  P(len_t) len;			/* largest match, zero otherwise */
-  P(char_t) c;			/* last character */
+  struct P(state) *from;	/* state with the previous character (forms a tree with null state in the root) */
+  struct P(state) *back;	/* backwards edge to the longest shorter state with same suffix */
+  struct P(state) *next;	/* the longest of shorter matches (or NULL) */
+  P(len_t) len;			/* state depth if it represents a key string, zero otherwise */
+  P(char_t) c;			/* last character of the represented string */
   struct {
 #   ifdef KMP_STATE_VARS
     KMP_STATE_VARS
-#   endif    
+#   endif
   } u;				/* user-defined data*/
 };
 
@@ -167,6 +213,10 @@ static inline void
 P(hash_init_key) (struct P(hash_table) *t UNUSED, struct P(state) *s, struct P(state) *f, P(char_t) c)
 {
   bzero(s, sizeof(*s));
+# ifdef KMP_INIT_STATE
+  struct P(struct) *kmp = (struct P(struct) *)t;
+  { KMP_INIT_STATE(kmp, s); }
+# endif
   s->from = f;
   s->c = c;
   s->next = f->back; /* the pointers hold the link-list of sons... changed in build() */
@@ -174,7 +224,7 @@ P(hash_init_key) (struct P(hash_table) *t UNUSED, struct P(state) *s, struct P(s
 }
 
 #undef P
-#define HASH_PREFIX(x) KMP_PREFIX(GLUE(hash_,x))
+#define HASH_PREFIX(x) KMP_PREFIX(hash_##x)
 #define HASH_NODE struct KMP_PREFIX(state)
 #define HASH_KEY_COMPLEX(x) x from, x c
 #define HASH_KEY_DECL struct KMP_PREFIX(state) *from, KMP_PREFIX(char_t) c
@@ -237,7 +287,7 @@ P(get_char) (struct P(struct) *kmp UNUSED, P(source_t) *src, P(char_t) *c)
   else if (!Ualpha(cc))
     cc = P(control)();
   else
-# endif  
+# endif
     {
 #     ifdef KMP_TOLOWER
       cc = Utolower(cc);
@@ -352,7 +402,7 @@ P(build) (struct P(struct) *kmp)
   null->back = NULL;
 # ifdef KMP_BUILD_STATE
   { KMP_BUILD_STATE(kmp, null); }
-# endif  
+# endif
   while (read != write)
     {
       struct P(state) *s = fifo[read++], *t;
@@ -375,7 +425,7 @@ P(build) (struct P(struct) *kmp)
 	}
 #     ifdef KMP_BUILD_STATE
       { KMP_BUILD_STATE(kmp, s); }
-#     endif      
+#     endif
     }
 }
 
@@ -396,6 +446,7 @@ P(build) (struct P(struct) *kmp)
 #undef KMP_ADD_INIT
 #undef KMP_ADD_NEW
 #undef KMP_ADD_DUP
+#undef KMP_INIT_STATE
 #undef KMP_BUILD_STATE
 #undef KMP_USE_POOL
 #undef KMP_GIVE_ALLOC