ledger/datetime.cc
2008-04-13 05:48:45 -04:00

381 lines
8.1 KiB
C++

#if defined(__GNUG__) && __GNUG__ < 3
#define _XOPEN_SOURCE
#endif
#include "datetime.h"
#include "error.h"
#include <ctime>
#include <cctype>
namespace ledger {
std::time_t now = std::time(NULL);
int now_year = std::localtime(&now)->tm_year;
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
};
char input_format[128];
const char * formats[] = {
"%Y/%m/%d",
"%m/%d",
"%Y.%m.%d",
"%m.%d",
"%Y-%m-%d",
"%m-%d",
"%a",
"%A",
"%b",
"%B",
"%Y",
NULL
};
std::time_t interval_t::first(const std::time_t moment) const
{
std::time_t quant = begin;
if (moment && std::difftime(moment, quant) > 0) {
// Find an efficient starting point for the upcoming while loop.
// We want a date early enough that the range will be correct, but
// late enough that we don't spend hundreds of thousands of loops
// skipping through time.
struct std::tm * desc = std::localtime(&moment);
if (years)
desc->tm_mon = 0;
desc->tm_mday = 1;
desc->tm_hour = 0;
desc->tm_min = 0;
desc->tm_sec = 0;
desc->tm_isdst = -1;
quant = std::mktime(desc);
std::time_t temp;
while (std::difftime(moment, temp = increment(quant)) >= 0) {
if (quant == temp)
break;
quant = temp;
}
}
return quant;
}
std::time_t interval_t::increment(const std::time_t moment) const
{
std::time_t then = moment;
if (years || months) {
struct std::tm * desc = std::localtime(&then);
if (years)
desc->tm_year += years;
if (months) {
desc->tm_mon += months;
if (desc->tm_mon > 11) {
desc->tm_year++;
desc->tm_mon -= 12;
}
else if (desc->tm_mon < 0) {
desc->tm_year--;
desc->tm_mon += 12;
}
}
desc->tm_hour = 0;
desc->tm_min = 0;
desc->tm_sec = 0;
desc->tm_isdst = -1;
then = std::mktime(desc);
}
return then + seconds;
}
static void parse_inclusion_specifier(const std::string& word,
std::time_t * begin,
std::time_t * end)
{
struct std::tm when;
if (! parse_date_mask(word.c_str(), &when))
throw interval_expr_error(std::string("Could not parse date mask: ") +
word);
when.tm_hour = 0;
when.tm_min = 0;
when.tm_sec = 0;
when.tm_isdst = -1;
bool saw_year = true;
bool saw_mon = true;
bool saw_day = true;
if (when.tm_year == -1) {
when.tm_year = now_year;
saw_year = false;
}
if (when.tm_mon == -1) {
when.tm_mon = 0;
saw_mon = false;
} else {
saw_year = false; // don't increment by year if month used
}
if (when.tm_mday == -1) {
when.tm_mday = 1;
saw_day = false;
} else {
saw_mon = false; // don't increment by month if day used
saw_year = false; // don't increment by year if day used
}
if (begin) {
*begin = std::mktime(&when);
if (end)
*end = interval_t(saw_day ? 86400 : 0, saw_mon ? 1 : 0,
saw_year ? 1 : 0).increment(*begin);
}
else if (end) {
*end = std::mktime(&when);
}
}
static inline void read_lower_word(std::istream& in, std::string& word) {
in >> word;
for (int i = 0, l = word.length(); i < l; i++)
word[i] = std::tolower(word[i]);
}
static void parse_date_words(std::istream& in, std::string& word,
std::time_t * begin, std::time_t * end)
{
std::string type;
bool mon_spec = false;
char buf[32];
if (word == "this" || word == "last" || word == "next") {
type = word;
if (! in.eof())
read_lower_word(in, word);
else
word = "month";
} else {
type = "this";
}
if (word == "month") {
std::strftime(buf, 31, "%B", std::localtime(&now));
word = buf;
mon_spec = true;
}
else if (word == "year") {
std::strftime(buf, 31, "%Y", std::localtime(&now));
word = buf;
}
parse_inclusion_specifier(word, begin, end);
if (type == "last") {
if (mon_spec) {
if (begin)
*begin = interval_t(0, -1, 0).increment(*begin);
if (end)
*end = interval_t(0, -1, 0).increment(*end);
} else {
if (begin)
*begin = interval_t(0, 0, -1).increment(*begin);
if (end)
*end = interval_t(0, 0, -1).increment(*end);
}
}
else if (type == "next") {
if (mon_spec) {
if (begin)
*begin = interval_t(0, 1, 0).increment(*begin);
if (end)
*end = interval_t(0, 1, 0).increment(*end);
} else {
if (begin)
*begin = interval_t(0, 0, 1).increment(*begin);
if (end)
*end = interval_t(0, 0, 1).increment(*end);
}
}
}
void interval_t::parse(std::istream& in)
{
std::string word;
while (! in.eof()) {
read_lower_word(in, word);
if (word == "every") {
read_lower_word(in, word);
if (std::isdigit(word[0])) {
int quantity = std::atol(word.c_str());
read_lower_word(in, word);
if (word == "days")
seconds = 86400 * quantity;
else if (word == "weeks")
seconds = 7 * 86400 * quantity;
else if (word == "months")
months = quantity;
else if (word == "quarters")
months = 3 * quantity;
else if (word == "years")
years = quantity;
}
else if (word == "day")
seconds = 86400;
else if (word == "week")
seconds = 7 * 86400;
else if (word == "month")
months = 1;
else if (word == "quarter")
months = 3;
else if (word == "year")
years = 1;
}
else if (word == "daily")
seconds = 86400;
else if (word == "weekly")
seconds = 7 * 86400;
else if (word == "biweekly")
seconds = 14 * 86400;
else if (word == "monthly")
months = 1;
else if (word == "bimonthly")
months = 2;
else if (word == "quarterly")
months = 3;
else if (word == "yearly")
years = 1;
else if (word == "this" || word == "last" || word == "next") {
parse_date_words(in, word, &begin, &end);
}
else if (word == "in") {
read_lower_word(in, word);
parse_date_words(in, word, &begin, &end);
}
else if (word == "from" || word == "since") {
read_lower_word(in, word);
parse_date_words(in, word, &begin, NULL);
}
else if (word == "to" || word == "until") {
read_lower_word(in, word);
parse_date_words(in, word, NULL, &end);
}
else {
parse_inclusion_specifier(word, &begin, &end);
}
}
}
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;
when.tm_isdst = -1;
if (when.tm_year == -1)
when.tm_year = ((year == -1) ? now_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(const char * date_str, std::time_t * result)
{
#if 1
return parse_date(date_str, result, now_year + 1900);
#else
int year = -1, month = -1, day, num = 0;
for (const 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 = now_year + 1900;
}
if (base == -1 || year != base_year) {
struct std::tm when;
std::memset(&when, 0, sizeof(when));
when.tm_isdst = -1;
base_year = year == -1 ? now_year + 1900 : year;
when.tm_year = year == -1 ? now_year : year - 1900;
when.tm_mday = 1;
base = std::mktime(&when);
year = base_year;
}
*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;
#endif
}
} // namespace ledger