beginings of a simple query engine

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@1151 57a11ea4-9604-0410-9ed3-97b8803252fd

src/engine/Makefile.in

@@ -35,7 +35,7 @@ CFLAGS   = @CFLAGS@ ${INCLPATH}
 ######################################################################
 # See Makefile.common for information about these variables.
 INDEP_SRCS := AccInfo.c Account.c DateUtils.c FileIO.c Group.c LedgerUtils.c \
-              QIFIO.c Transaction.c TransLog.c date.c util.c
+              QIFIO.c Query.c Transaction.c TransLog.c date.c util.c
 ######################################################################
 
 all: default

src/engine/Query.c

@@ -0,0 +1,188 @@
+/*
+ * FILE:
+ * Query.c
+ *
+ * DESCRIPTION:
+ * Provide a simple query engine interface.
+ *
+ * HISTORY:
+ * created by Linas Vepstas Sept 1998
+ * Copyright (c) 1998 Linas Vepstas
+ */
+
+#include "config.h"
+#include "Query.h"
+#include "util.h"
+
+struct _Query {
+   Account ** acc_list;
+
+   /* maximum number of splits to return */
+   int max_num_splits;
+
+   char changed;     /* flag, has the query changed? */
+   Split **split_list;
+};
+
+/* ================================================== */
+
+Query *
+xaccMallocQuery (void)
+{
+   Query * ret;
+   ret =  (Query *) _malloc (sizeof (Query));
+   xaccInitQuery (ret);
+   return ret;
+}
+
+/* ================================================== */
+
+void 
+xaccInitQuery (Query *q)
+{
+   if (!q) return;
+
+   q->acc_list = NULL;
+   q->split_list = NULL;
+   q->changed = 0; 
+   q->max_num_splits = 2<<30;
+}
+
+/* ================================================== */
+
+void 
+xaccFreeQuery (Query *q)
+{
+   if (!q) return;
+
+   if (q->acc_list) _free (q->acc_list);
+   q->acc_list = 0x0;
+
+   if (q->split_list) _free (q->split_list);
+   q->split_list = 0x0;
+
+   _free (q);
+}
+
+/* ================================================== */
+
+void
+xaccQuerySetAccounts (Query *q, Account **list)
+{
+   int i=0;
+   Account *acc;
+
+   if (!q || !list) return;
+   q->changed = 1; 
+   
+   i=0; acc = list[0];
+   while (acc) {
+      i++;  acc = list[i];
+   }  
+
+   if (q->acc_list) free (q->acc_list);
+
+   q->acc_list = (Account **) _malloc ( (i+1) * sizeof (Account *));
+
+   i=0; acc = list[0];
+   while (acc) {
+      q->acc_list[i] = acc;
+      i++;  acc = list[i];
+   }  
+   q->acc_list[i] = NULL;
+}
+
+/* ================================================== */
+
+void
+xaccQueryAddAccount (Query *q, Account *addme)
+{
+   int i=0;
+   Account *acc;
+   Account **oldlist;
+
+   if (!q || !addme) return;
+   q->changed = 1; 
+   
+   oldlist = q->acc_list;
+   i = 0;
+   if (oldlist) {
+      i=0; acc = oldlist[0];
+      while (acc) {
+         i++;  acc = oldlist[i];
+      }  
+   }
+
+   q->acc_list = (Account **) _malloc ( (i+2) * sizeof (Account *));
+
+   i=0; acc = oldlist[0];
+   while (acc) {
+      q->acc_list[i] = acc;
+      i++;  acc = oldlist[i];
+   }  
+   q->acc_list[i] = addme;
+   i++;
+   q->acc_list[i] = NULL;
+
+   if (oldlist) free (oldlist);
+}
+
+/* ================================================== */
+
+void  
+xaccQuerySetMaxSplits (Query *q, int max)
+{
+   if (!q) return;
+   q->max_num_splits = max;
+}
+
+/* ================================================== */
+
+Split **
+xaccQueryGetSplits (Query *q)
+{
+   int i=0, j=0;
+   int nlist, nstart, nret;
+   Split *s, **slist;
+
+   if (!q) return NULL;
+
+   /* if not changed then don't recompute cache */
+   if (!(q->changed)) return q->split_list;
+   q->changed = 0;
+
+   if (q->split_list) _free (q->split_list);
+   q->split_list = NULL;
+
+   /* hack alert */
+   slist = xaccAccountGetSplitList (q->acc_list[0]);
+   if (!slist) return NULL;
+
+   i=0; s = slist[0];
+   while (s) { i++; s = slist [i]; }
+   nlist = i;
+   
+   /* make sure we don't return too many splits */
+   nret = nlist;
+   if (nret > q->max_num_splits) nret = q->max_num_splits;
+   q->split_list =  (Split **) malloc ((nret+1) * sizeof (Split *));
+   
+   /* return only the last few splits */
+   nstart = nlist - nret;
+   if (0 > nstart) nstart = 0;
+
+   /* copy over */
+   i=nstart; s = slist[i];
+   j = 0;
+   while (s) { 
+      q->split_list [j] = s;
+      j++; i++; s = slist [i];
+   }
+   q->split_list [j] = NULL;
+   
+   return q->split_list;
+}
+
+/* ================================================== */
+
+

src/engine/Query.h

@@ -0,0 +1,48 @@
+/*
+ * FILE:
+ * Query.h
+ *
+ * DESCRIPTION:
+ * Provide a simple query engine interface.
+ *
+ * HISTORY:
+ * created by Linas Vepstas Sept 1998
+ * Copyright (c) 1998 Linas Vepstas
+ */
+
+#ifndef __GNUCASH_QUERY_H__
+#define __GNUCASH_QUERY_H__
+
+#include "Account.h"
+#include "Transaction.h"
+
+typedef struct _Query Query;
+
+/* sorting orders */
+enum {
+  BY_DATE,
+  BY_NUM,
+  BY_AMOUNT
+};
+
+Query * xaccMallocQuery (void);
+void    xaccInitQuery (Query *);
+void    xaccFreeQuery (Query *);
+
+/* The xaccSetAccountList() method is used to define the set
+ *    of accounts the should be queried.
+ */
+void xaccQuerySetAccounts (Query *, Account **list);
+void xaccQueryAddAccount (Query *, Account *acc);
+
+/* The xaccQuerySetMaxSplits() method sets the maximum number
+ *    of splits to return as a result of a query.
+ */
+void  xaccQuerySetMaxSplits (Query *, int);
+
+/* The xaccQueryGetSplits() method returns a list of splits
+ * matching the query and sorting criteria previously set up.
+ */
+Split ** xaccQueryGetSplits (Query *);
+
+#endif /* __GNUCASH_QUERY_H__ */