fix problem of saving rdbmap when coring in a malloc/free.

BigFile.cpp

@@ -165,6 +165,18 @@ bool BigFile::addPart ( int32_t n ) {
 		char *xx=NULL;*xx=0;}
 	// how much more mem do we need?
 	int32_t delta = need - m_fileBuf.getLength();
+
+	// avoid a malloc for small files.
+	// this way we can save in memory RdbMaps upon a core, even malloc/free
+	// related cores, cuz we won't have to do a malloc to save!
+	if ( delta <= LITTLEBUFSIZE && ! m_fileBuf.m_buf ) {
+		m_fileBuf.m_usingStack = true;
+		m_fileBuf.m_buf        = m_littleBuf;
+		m_fileBuf.m_capacity   = LITTLEBUFSIZE;
+		m_fileBuf.m_length     = 0;
+		// do not call reserve() below:
+		delta = 0;
+	}
 	// . make sure our CAPACITY is increased by what we need
 	// . SafeBuf::reserve() ADDS this much to current capacity
 	// . true = clear new mem so File::m_calledSet is false for Files

BigFile.h

@@ -31,6 +31,8 @@ ssize_t gbpwrite(int fd, const void *buf, size_t count, off_t offset);
 // debug define
 //#define MAX_PART_FILES 100
 
+#define LITTLEBUFSIZE 80
+
 // use this state class for doing non-blocking reads/writes
 #ifdef ASYNCIO
 #include <aio.h> // TODO: use kaio, uses only 4 threads
@@ -263,6 +265,8 @@ class BigFile {
 	// to hold the array of Files
 	SafeBuf m_fileBuf;
 
+	char m_littleBuf[LITTLEBUFSIZE];
+
 	// ptrs to the part files
 	//File *m_files ;//[ MAX_PART_FILES ];
 

RdbMap.cpp

@@ -93,6 +93,8 @@ void RdbMap::reset ( ) {
 	m_lastLogTime = 0;
 	m_badKeys     = 0;
 	m_needVerify  = false;
+
+	m_file.reset();
 }
 
 

SafeBuf.h

@@ -388,7 +388,7 @@ public:
 public:
 	int32_t  m_capacity;
 	int32_t  m_length;
-protected:
+	//protected:
 	char *m_buf;
 public:
 	char *m_label;