rewrote the way registers are computed -- again

1 files changed, 125 insertions, 0 deletions

diff --git a/datetime.cc b/datetime.cc
new file mode 100644
index 00000000..19f54f92
--- /dev/null
+++ b/datetime.cc
@@ -0,0 +1,125 @@
+#include "datetime.h"
+
+#include <ctime>
+
+namespace ledger {
+
+static std::time_t	now	  = std::time(NULL);
+       struct std::tm * now_tm	  = std::localtime(&now);
+
+static std::time_t	base      = -1;
+static int		base_year = -1;
+
+static const int	month_days[12] = {
+  31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+static const char *	formats[] = {
+  "%Y/%m/%d",
+  "%m/%d",
+  "%Y.%m.%d",
+  "%m.%d",
+  "%Y-%m-%d",
+  "%m-%d",
+  "%a",
+  "%A",
+  "%b",
+  "%B",
+  "%Y",
+  NULL
+};
+
+bool parse_date_mask(const char * date_str, struct std::tm * result)
+{
+  for (const char ** f = formats; *f; f++) {
+    memset(result, INT_MAX, sizeof(struct std::tm));
+    if (strptime(date_str, *f, result))
+      return true;
+  }
+  return false;
+}
+
+bool parse_date(const char * date_str, std::time_t * result, const int year)
+{
+  struct std::tm when;
+
+  if (! parse_date_mask(date_str, &when))
+    return false;
+
+  when.tm_hour = 0;
+  when.tm_min  = 0;
+  when.tm_sec  = 0;
+
+  if (when.tm_year == -1)
+    when.tm_year = ((year == -1) ? now_tm->tm_year : (year - 1900));
+
+  if (when.tm_mon == -1)
+    when.tm_mon = 0;
+
+  if (when.tm_mday == -1)
+    when.tm_mday = 1;
+
+  *result = std::mktime(&when);
+
+  return true;
+}
+
+bool quick_parse_date(char * date_str, std::time_t * result)
+{
+  int year = -1, month = -1, day, num = 0;
+
+  for (char * p = date_str; *p; p++) {
+    if (*p == '/' || *p == '-' || *p == '.') {
+      if (year == -1)
+	year = num;
+      else
+	month = num;
+      num = 0;
+    }
+    else if (*p < '0' || *p > '9') {
+      return false;
+    }
+    else {
+      num *= 10;
+      num += *p - '0';
+    }
+  }
+
+  day = num;
+
+  if (month == -1) {
+    month = year;
+    year  = -1;
+  }
+
+  if (base == -1 || year != base_year) {
+    struct std::tm when;
+
+    when.tm_hour = 0;
+    when.tm_min  = 0;
+    when.tm_sec  = 0;
+
+    base_year    = year == -1 ? now_tm->tm_year + 1900 : year;
+    when.tm_year = year == -1 ? now_tm->tm_year : year - 1900;
+    when.tm_mon  = 0;
+    when.tm_mday = 1;
+
+    base = std::mktime(&when);
+  }
+
+  *result = base;
+
+  --month;
+  while (--month >= 0) {
+    *result += month_days[month] * 24 * 60 * 60;
+    if (month == 1 && year % 4 == 0 && year != 2000) // february in leap years
+      *result += 24 * 60 * 60;
+  }
+
+  if (--day)
+    *result += day * 24 * 60 * 60;
+
+  return true;
+}
+
+} // namespace ledger