Get edge splitting working

test.c

@@ -3,14 +3,19 @@
 #include "trie.h"
 
 #include <sys/stat.h>
+#include <stdlib.h>
 
 bool ffdb_test()
 {
 	const char* d = "/tmp/ffdb-test";
+	system( "rm -Rvf /tmp/ffdb-test" );
 	mkdir( d, 0755 );
-	ffdb_trie_set( d, "https://example.com/actor", "T" );
-	//ffdb_trie_set( d, "https://apogee.polaris-1.work/owner/actor", "T" );
 
-	return false;
+	bool result = true;
+
+	result &= ffdb_trie_set( d, "https://example.com/actor", "T" );
+	result &= ffdb_trie_set( d, "https://apogee.polaris-1.work/owner/actor", "T" );
+
+	return result;
 }
 

trie.c

@@ -22,11 +22,27 @@ struct edge {
 
 struct trie_entry
 {
-	struct edge* edges;
+	struct {
-	int count;
+		struct edge* items;
+		int count;
+	} edges;
+	char* filename;
 };
 
-static bool load_entry( FILE* f, struct trie_entry* e )
+static void trie_entry_free( struct trie_entry* e )
+{
+	if( !e ) { return; }
+
+	for( int i = 0; i < e->edges.count; ++i ) {
+		free(e->edges.items[i].label);
+		free(e->edges.items[i].value);
+	}
+	free(e->edges.items);
+	free(e->filename);
+	free(e);
+}
+
+static bool trie_entry_load( FILE* f, struct trie_entry* e )
 {
 	struct json_pull_parser jpp = {
 		.f = f,
@@ -37,13 +53,13 @@ static bool load_entry( FILE* f, struct trie_entry* e )
 	int save;
 	if( !json_pull_parser_begin_object(&jpp,&save) ) { goto failed; }
 
-	e->count = 0;
+	e->edges.count = 0;
 
 	char* edge_label = NULL;
 	while( edge_label = json_pull_parser_read_object_key(&jpp) ) {
-		e->count += 1;
+		e->edges.count += 1;
-		e->edges = realloc( e->edges, sizeof(struct edge) * e->count );
+		e->edges.items = realloc( e->edges.items, sizeof(struct edge) * e->edges.count );
-		struct edge* ed = &e->edges[ e->count-1 ];
+		struct edge* ed = &e->edges.items[ e->edges.count-1 ];
 		memset(ed,0,sizeof(*ed));
 
 		ed->label = edge_label;
@@ -63,18 +79,30 @@ failed:
 	fclose(jpp.f);
 	return false;
 }
+static bool trie_entry_load_from_file( const char* filename, struct trie_entry* e )
+{
+	e->filename = strdup(filename);
 
-static void save_entry( FILE* f, struct trie_entry* e )
+	FILE* f = fopen( filename, "r" );
+	if( !f ) { return false; }
+
+	bool result = trie_entry_load( f, e );
+	fclose(f);
+
+	return result;
+}
+
+static void trie_entry_save( FILE* f, struct trie_entry* e )
 {
 	fprintf( f, "{" );
-	for( int i = 0; i < e->count; ++i ) {
+	for( int i = 0; i < e->edges.count; ++i ) {
 		if( i != 0 ) {
 			fprintf( f, ",\n\t" );
 		} else {
 			fprintf( f, "\n\t" );
 		}
 
-		struct edge* ed = &e->edges[i];
+		struct edge* ed = &e->edges.items[i];
 		json_write_string( f, ed->label );
 		fprintf( f, ": " );
 		if( ed->count > 1 ) {
@@ -85,6 +113,19 @@ static void save_entry( FILE* f, struct trie_entry* e )
 	}
 	fprintf( f, "\n}\n" );
 }
+static bool trie_entry_save_to_file( const char* filename, struct trie_entry* e )
+{
+	char tmp_filename[512];
+	snprintf( tmp_filename, sizeof(tmp_filename), "%s.tmp", filename );
+	FILE* f = fopen(tmp_filename,"w");
+	if( !f ) { return false; }
+
+	trie_entry_save( f, e );
+
+	fclose(f);
+	rename( tmp_filename, filename );
+	return true;
+}
 
 // Escape '/' as "%|" and '%' as "%%"
 static char* escape( const char* str )
@@ -119,7 +160,7 @@ static char* escape( const char* str )
 	}
 	*o = '\0';
 
-	return o;
+	return result;
 }
 
 static int prefix_match( const char* a, const char* b )
@@ -133,62 +174,119 @@ static int prefix_match( const char* a, const char* b )
 	return res;
 }
 
-static bool trie_set( struct trie_entry* e, const char* key, const char* value )
+static bool trie_entry_set( struct trie_entry* e, const char* key, const char* value )
 {
-	for( int i = 0; i < e->count; ++i ) {
+	int prefix_len = 0;
-		struct edge* ed = &e->edges[i];
+	struct edge* ed;
+
+	printf( "key: %s\n", key );
+	for( int i = 0; i < e->edges.count; ++i ) {
+		ed = &e->edges.items[i];
+		printf( "label[%d]: %s\n", i, ed->label );
+		fflush(stdout);
 
-		int prefix_len = prefix_match( key, ed->label );
+		prefix_len = prefix_match( key, ed->label );
 		if( prefix_len == strlen( ed->label ) ) {
-			if( ed->count == 1 ) {
+			goto traverse_existing_edge;
-				free(ed->value);
-				ed->value = strdup(value);
-				return true;
-			} else {
-				printf( "TODO: exact match, go down this node\n" );
-			}
-			return false;
 		} else if( prefix_len != 0 ) {
-			printf( "TODO: create new node" );
+			goto split_existing_edge;
-			return false;
 		}
 	}
 
-	// No match in node, add
+	goto add_new_edge;
-	printf( "Adding edge %s\n", key );
+
-	e->count += 1;
+add_new_edge:
-	e->edges = realloc( e->edges, sizeof(struct edge) * e->count );
+	{
-	struct edge* ed = &e->edges[e->count-1];
+		printf( "Adding edge %s\n", key );
-	ed->label = strdup(key);
+		e->edges.count += 1;
-	ed->value = strdup(value);
+		e->edges.items = realloc( e->edges.items, sizeof(struct edge) * e->edges.count );
-	ed->count = 1;
+
+		struct edge* ed2 = &e->edges.items[e->edges.count-1];
+		ed2->label = strdup(key);
+		ed2->value = strdup(value);
+		ed2->count = 1;
+	}
+	return trie_entry_save_to_file( e->filename, e );
+
+traverse_existing_edge:
+	if( ed->count == 1 ) {
+		free(ed->value);
+		ed->value = strdup(value);
+		return true;
+	}
+
+	printf( "TODO: exact match, go down this node\n" );
+	return false;
+
+split_existing_edge:
+	{
+		char* new_prefix = strndup( key, prefix_len );
+		char* new_filename = malloc(strlen(e->filename)+prefix_len+1);
+		strcpy(new_filename,e->filename);
+		strcat(new_filename,new_prefix);
+
+		// Create the new node
+		struct trie_entry* new_e = malloc(sizeof(struct trie_entry));
+		memset(new_e,0,sizeof(*new_e));
+		new_e->filename = new_filename;
+
+		new_e->edges.items = malloc( sizeof(struct edge) * 2 );
+		new_e->edges.items[0].label = strdup(&ed->label[prefix_len]);
+		new_e->edges.items[0].value = ed->value;
+		new_e->edges.items[0].count = 1;
+
+		new_e->edges.items[1].label = strdup(&key[prefix_len]);
+		new_e->edges.items[1].value = strdup(value);
+		new_e->edges.items[1].count = 1;
+		new_e->edges.count = 2;
+
+		// Save to file
+		trie_entry_save_to_file( new_e->filename, new_e );
+		trie_entry_free(new_e);
+
+		// Update the existing edge
+		free(ed->label);
+		ed->label = new_prefix;
+		ed->value = NULL;
+		ed->count = 2;
+		trie_entry_save_to_file( e->filename, e );
+	}
 	return true;
 }
 
+static struct trie_entry* load_root_node( const char* filename )
+{
+	struct trie_entry* root = malloc(sizeof(*root));
+	memset(root,0,sizeof(*root));
+
+	char buffer[512];
+	snprintf( buffer, sizeof(buffer), "%s/%ROOT|", filename );
+	trie_entry_load_from_file( buffer, root );
+
+	return root;
+}
+
 bool ffdb_trie_set( const char* filename, const char* key, const char* value )
 {
+	struct trie_entry* root = NULL;
 	char* key_escaped = escape(key);
+	bool result = false;
 
-	struct trie_entry root;
+	root = load_root_node(filename);
-	memset(&root,0,sizeof(root));
 
-	char buffer[512];
+	if( !trie_entry_set( root, key_escaped, value ) ) {
-	snprintf( buffer, sizeof(buffer), "%s/%ROOT", filename );
-	FILE* f = fopen( buffer, "r" );
-	if( f ) {
-		load_entry( f, &root );
-	}
-
-	if( !trie_set( &root, key, value ) ) {
 		printf( "Failed to set %s to %s\n", key, value );
-		return false;
+		goto failed;
 	}
 
-	f = fopen( buffer, "w" );
+	result = true;
-	save_entry( f, &root );
+cleanup:
-	fclose(f);
+	free(key_escaped);
-
+	trie_entry_free(root);
-	return true;
+	return result;
+failed:
+	result = false;
+	goto cleanup;
 }
 char* ffdb_trie_get( const char* filename, const char* key )
 {
@@ -200,8 +298,23 @@ bool ffdb_trie_remove( const char* filename, const char* key )
 }
 int ffdb_trie_count( const char* filename )
 {
-	return 0;
+	struct trie_entry* root = NULL;
+	int result = 0;
+
+	root = load_root_node(filename);
+	if( !root ) { goto failed; }
+
+	for( int i = 0; i < root->edges.count; ++i ) {
+		result += root->edges.items[i].count;
+	}
+cleanup:
+	trie_entry_free(root);
+	return result;
+failed:
+	result = -1;
+	goto cleanup;
 }
+
 void ffdb_trie_clean( const char* filename )
 {
 }