sorting optimization

ledger.texi

@@ -1050,14 +1050,14 @@ beginning of the ledger.  For food spending just this month
 (September), use:
 
 @example
-ledger -d sep balance expenses:food
+ledger -p sep balance expenses:food
 @end example
 
 Or maybe I want to see all of my assets, in which case the -s (show
 sub-accounts) option comes in handy:
 
 @example
-ledger balance -s
+ledger -s balance
 @end example
 
 To exclude a particular account, use a regular expression with a
@@ -1068,13 +1068,20 @@ food spending:
 ledger balance expenses -food
 @end example
 
-If you want to show all accounts but for one account, remember to use
+A query like the following will show the largest expense categories
-``--'' to separate the exclusion pattern from the options list:
+since a given date:
 
 @example
-ledger balance -- -equity
+ledger -b 2003/10 -s -S -AT -d "T>1000" bal ^expenses -internet
 @end example
 
+From left to right the options used mean: Show entries since October,
+2003; showa all sub-accounts; sort in verse order by the absolute
+value of the total; display only accounts with a total value greater
+than 1000 units (of whichever commodities the account contains); and
+report the balance for all expenses, except for those matching
+``internet''.
+
 @node File format,  , Typical queries, Running Ledger
 @section File format
 

walk.cc

@@ -9,6 +9,28 @@ std::list<void **>	       transactions_xdata_ptrs;
 std::list<account_xdata_t>     accounts_xdata;
 std::list<void **>	       accounts_xdata_ptrs;
 
+template <>
+bool compare_items<transaction_t>::operator()(const transaction_t * left,
+					      const transaction_t * right)
+{
+  assert(left);
+  assert(right);
+
+  transaction_xdata_t& lxdata(transaction_xdata(*left));
+  if (! (lxdata.dflags & TRANSACTION_SORT_CALC)) {
+    sort_order->compute(lxdata.sort_value, details_t(*left));
+    lxdata.dflags |= TRANSACTION_SORT_CALC;
+  }
+
+  transaction_xdata_t& rxdata(transaction_xdata(*right));
+  if (! (rxdata.dflags & TRANSACTION_SORT_CALC)) {
+    sort_order->compute(rxdata.sort_value, details_t(*right));
+    rxdata.dflags |= TRANSACTION_SORT_CALC;
+  }
+
+  return lxdata.sort_value < rxdata.sort_value;
+}
+
 void sort_transactions::flush()
 {
   std::stable_sort(transactions.begin(), transactions.end(),
@@ -123,7 +145,7 @@ static void handle_value(const value_t&		       value,
   }
 }
 
-void determine_amount(value_t& result, balance_pair_t& bal_pair)
+static inline void determine_amount(value_t& result, balance_pair_t& bal_pair)
 {
   account_xdata_t xdata;
   xdata.value = bal_pair;
@@ -319,6 +341,28 @@ void clear_transactions_xdata()
     **i = NULL;
 }
 
+template <>
+bool compare_items<account_t>::operator()(const account_t * left,
+					  const account_t * right)
+{
+  assert(left);
+  assert(right);
+
+  account_xdata_t& lxdata(account_xdata(*left));
+  if (! (lxdata.dflags & ACCOUNT_SORT_CALC)) {
+    sort_order->compute(lxdata.sort_value, details_t(*left));
+    lxdata.dflags |= ACCOUNT_SORT_CALC;
+  }
+
+  account_xdata_t& rxdata(account_xdata(*right));
+  if (! (rxdata.dflags & ACCOUNT_SORT_CALC)) {
+    sort_order->compute(rxdata.sort_value, details_t(*right));
+    rxdata.dflags |= ACCOUNT_SORT_CALC;
+  }
+
+  return lxdata.sort_value < rxdata.sort_value;
+}
+
 void sum_accounts(account_t& account)
 {
   for (accounts_map::iterator i = account.accounts.begin();

walk.h

@@ -38,28 +38,37 @@ struct item_handler {
 
 template <typename T>
 class compare_items {
-  value_t left_result;
-  value_t right_result;
-
   const value_expr_t * sort_order;
-
  public:
   compare_items(const value_expr_t * _sort_order)
     : sort_order(_sort_order) {
     assert(sort_order);
   }
-
+  bool operator()(const T * left, const T * right);
-  bool operator()(const T * left, const T * right) {
-    assert(left);
-    assert(right);
-
-    sort_order->compute(left_result, details_t(*left));
-    sort_order->compute(right_result, details_t(*right));
-
-    return left_result < right_result;
-  }
 };
 
+template <typename T>
+bool compare_items<T>::operator()(const T * left, const T * right)
+{
+  assert(left);
+  assert(right);
+
+  value_t left_result;
+  value_t right_result;
+  sort_order->compute(left_result, details_t(*left));
+  sort_order->compute(right_result, details_t(*right));
+
+  return left_result < right_result;
+}
+
+template <>
+bool compare_items<transaction_t>::operator()(const transaction_t * left,
+					      const transaction_t * right);
+
+template <>
+bool compare_items<account_t>::operator()(const account_t * left,
+					  const account_t * right);
+
 //////////////////////////////////////////////////////////////////////
 //
 // Transaction handlers
@@ -69,10 +78,12 @@ class compare_items {
 #define TRANSACTION_TO_DISPLAY 0x0002
 #define TRANSACTION_DISPLAYED  0x0004
 #define TRANSACTION_NO_TOTAL   0x0008
+#define TRANSACTION_SORT_CALC  0x0010
 
 struct transaction_xdata_t
 {
   value_t	 total;
+  value_t	 sort_value;
   unsigned int   index;
   unsigned short dflags;
 
@@ -400,11 +411,13 @@ class related_transactions : public item_handler<transaction_t>
 
 #define ACCOUNT_TO_DISPLAY 0x1
 #define ACCOUNT_DISPLAYED  0x2
+#define ACCOUNT_SORT_CALC  0x4
 
 struct account_xdata_t
 {
   value_t	 value;
   value_t	 total;
+  value_t	 sort_value;
   unsigned int   count;	// transactions counted toward total
   unsigned int   subcount;
   unsigned short dflags;