From 43374a25b92c74d6c566d1b53d47503a28680996 Mon Sep 17 00:00:00 2001
From: Giovanni Bussi <giovanni.bussi@gmail.com>
Date: Wed, 28 Aug 2013 19:28:16 +0200
Subject: [PATCH] Optimized OFile
Removed many scans of the output buffer by keeping trace of buffer length.
Time needed to write a long line with a sequence of file.printf() is
now linear with line length. Before it was quatradic, causing problems
especially when logging huge atom lists at startup.
---
src/tools/OFile.cpp | 25 ++++++++++++++-----------
src/tools/OFile.h | 2 ++
2 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/src/tools/OFile.cpp b/src/tools/OFile.cpp
index 7820ee202..5ff9a73a1 100644
--- a/src/tools/OFile.cpp
+++ b/src/tools/OFile.cpp
@@ -53,6 +53,7 @@ OFile::OFile():
{
fmtField();
buflen=1;
+ actual_buffer_length=0;
buffer=new char[buflen];
// these are set to zero to avoid valgrind errors
for(unsigned i=0;i<buflen;++i) buffer[i]=0;
@@ -78,14 +79,13 @@ OFile& OFile::setLinePrefix(const std::string&l){
}
int OFile::printf(const char*fmt,...){
- size_t pointer=strlen(buffer);
va_list arg;
va_start(arg, fmt);
- int r=std::vsnprintf(&buffer[pointer],buflen-pointer,fmt,arg);
+ int r=std::vsnprintf(&buffer[actual_buffer_length],buflen-actual_buffer_length,fmt,arg);
va_end(arg);
- if(r>=buflen-pointer){
+ if(r>=buflen-actual_buffer_length){
int newlen=buflen;
- while(newlen<=r+pointer) newlen*=2;
+ while(newlen<=r+actual_buffer_length) newlen*=2;
char* newbuf=new char [newlen];
memmove(newbuf,buffer,buflen);
for(int k=buflen;k<newlen;k++) newbuf[k]=0;
@@ -94,22 +94,25 @@ int OFile::printf(const char*fmt,...){
buflen=newlen;
va_list arg;
va_start(arg, fmt);
- r=std::vsnprintf(&buffer[pointer],buflen-pointer,fmt,arg);
+ r=std::vsnprintf(&buffer[actual_buffer_length],buflen-actual_buffer_length,fmt,arg);
va_end(arg);
}
- plumed_massert(r>-1 && r<buflen-pointer,"error using fmt string " + std::string(fmt));
+ plumed_massert(r>-1 && r<buflen-actual_buffer_length,"error using fmt string " + std::string(fmt));
// Line is buffered until newline, then written with a PLUMED: prefix
char*p1=buffer;
char*p2;
- while((p2=strchr(p1,'\n'))){
- *p2='\0';
+// newline is only searched in the just added portion:
+ char*psearch=p1+actual_buffer_length;
+ actual_buffer_length+=r;
+ while((p2=strchr(psearch,'\n'))){
if(linePrefix.length()>0) llwrite(linePrefix.c_str(),linePrefix.length());
- llwrite(p1,std::strlen(p1));
- llwrite("\n",1);
+ llwrite(p1,p2-p1+1);
+ actual_buffer_length-=(p2-p1)+1;
p1=p2+1;
+ psearch=p1;
};
- memmove(buffer,p1,strlen(p1)+1);
+ if(buffer!=p1) memmove(buffer,p1,actual_buffer_length);
return r;
}
diff --git a/src/tools/OFile.h b/src/tools/OFile.h
index 74732c167..fe08c9dce 100644
--- a/src/tools/OFile.h
+++ b/src/tools/OFile.h
@@ -92,6 +92,8 @@ public virtual FileBase{
char* buffer;
/// Internal buffer length
int buflen;
+/// This variables stores the actual buffer length
+ unsigned actual_buffer_length;
/// Class identifying a single field for fielded output
class Field:
public FieldBase{
--
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