Fix log head/tail functions.

[dcpomatic.git] / src / lib / log.cc

diff --git a/src/lib/log.cc b/src/lib/log.cc
index 52dff2982222620d81a9b7426c13c2a32beb523e..934664915b0e5d9d4608a2e81276315ba7553544 100644 (file)
--- a/src/lib/log.cc
+++ b/src/lib/log.cc
@@ -26,6 +26,7 @@
 #include "log.h"
 #include "cross.h"
 #include "config.h"
+#include "safe_stringstream.h"
 
 #include "i18n.h"
 
@@ -39,7 +40,7 @@ int const Log::TYPE_TIMING  = 0x8;
 Log::Log ()
        : _types (0)
 {
-       Config::instance()->Changed.connect (boost::bind (&Log::config_changed, this));
+       _config_connection = Config::instance()->Changed.connect (boost::bind (&Log::config_changed, this));
        config_changed ();
 }
 
@@ -63,7 +64,7 @@ Log::log (string message, int type)
        time (&t);
        string a = ctime (&t);
 
-       stringstream s;
+       SafeStringStream s;
        s << a.substr (0, a.length() - 1) << N_(": ");
 
        if (type & TYPE_ERROR) {
@@ -90,7 +91,7 @@ Log::microsecond_log (string m, int t)
        struct timeval tv;
        gettimeofday (&tv, 0);
 
-       stringstream s;
+       SafeStringStream s;
        s << tv.tv_sec << N_(":") << tv.tv_usec << N_(" ") << m;
        do_log (s.str ());
 }      
@@ -122,3 +123,45 @@ FileLog::do_log (string m)
        fclose (f);
 }
 
+string
+FileLog::head_and_tail (int amount) const
+{
+       boost::mutex::scoped_lock lm (_mutex);
+
+       uintmax_t head_amount = amount;
+       uintmax_t tail_amount = amount;
+       uintmax_t size = boost::filesystem::file_size (_file);
+
+       if (size < (head_amount + tail_amount)) {
+               head_amount = size;
+               tail_amount = 0;
+       }
+       
+       FILE* f = fopen_boost (_file, "r");
+       if (!f) {
+               return "";
+       }
+
+       string out;
+
+       char* buffer = new char[max(head_amount, tail_amount) + 1];
+       
+       int N = fread (buffer, 1, head_amount, f);
+       buffer[N] = '\0';
+       out += string (buffer);
+
+       if (tail_amount > 0) {
+               out +=  "\n.\n.\n.\n";
+
+               fseek (f, - tail_amount - 1, SEEK_END);
+               
+               N = fread (buffer, 1, tail_amount, f);
+               buffer[N] = '\0';
+               out += string (buffer) + "\n";
+       }
+
+       delete[] buffer;
+       fclose (f);
+
+       return out;
+}