Move most platform-specific code into overlay directories

[libs/core.git] / source / time / unix / timezone.cpp

diff --git a/source/time/unix/timezone.cpp b/source/time/unix/timezone.cpp
new file mode 100644 (file)
index 0000000..e55969c
--- /dev/null
+++ b/source/time/unix/timezone.cpp
@@ -0,0 +1,85 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include "timestamp.h"
+#include "timezone.h"
+#include "utils.h"
+
+using namespace std;
+
+namespace {
+
+long get_long(char *&ptr)
+{
+       long result = 0;
+       for(unsigned i=0; i<4; ++i)
+               result = (result<<8)+static_cast<unsigned char >(*ptr++);
+       return result;
+}
+
+}
+
+
+namespace Msp {
+namespace Time {
+
+TimeZone TimeZone::platform_get_local_timezone()
+{
+       int fd = open("/etc/localtime", O_RDONLY);
+       if(fd!=-1)
+       {
+               char hdr[44];
+               int len = read(fd, hdr, sizeof(hdr));
+               long gmtoff = -1;
+               string name;
+               if(len==44 && hdr[0]=='T' && hdr[1]=='Z' && hdr[2]=='i' && hdr[3]=='f')
+               {
+                       char *ptr = hdr+20;
+                       long isgmtcnt = get_long(ptr);
+                       long isstdcnt = get_long(ptr);
+                       long leapcnt = get_long(ptr);
+                       long timecnt = get_long(ptr);
+                       long typecnt = get_long(ptr);
+                       long charcnt = get_long(ptr);
+                       int size = timecnt*5+typecnt*6+isgmtcnt+isstdcnt+leapcnt*8+charcnt;
+                       char *buf = new char[size];
+                       len = read(fd, buf, size);
+                       if(len==size)
+                       {
+                               ptr = buf;
+                               int index = -1;
+                               time_t cur_time = Msp::Time::now().to_unixtime();
+                               for(int i=0; i<timecnt; ++i)
+                                       if(get_long(ptr)<=cur_time)
+                                               index = i;
+
+                               if(index>0)
+                                       index = ptr[index];
+                               ptr += timecnt;
+
+                               int abbrind = 0;
+                               for(int i=0; i<typecnt; ++i)
+                               {
+                                       if((index>=0 && i==index) || (index<0 && !ptr[4] && gmtoff==-1))
+                                       {
+                                               gmtoff = get_long(ptr);
+                                               ++ptr;
+                                               abbrind = *ptr++;
+                                       }
+                                       else
+                                               ptr += 6;
+                               }
+
+                               name = ptr+abbrind;
+                       }
+                       delete[] buf;
+               }
+               close(fd);
+
+               if(gmtoff!=-1)
+                       return TimeZone(gmtoff/60, name);
+       }
+       return TimeZone();
+}
+
+} // namespace Time
+} // namespace Msp