add mmap library.

CHANGES

@@ -1,3 +1,7 @@
+0.7:
+  oops, the read buffering was completely broken!
+  add mmap library (idea from Ingo Oeser)
+
 0.6:
   changed name to libowfat.
   fixed fmt_ulong (did not output 0 correctly).

Makefile

@@ -1,6 +1,6 @@
-all: t byte.a fmt.a scan.a str.a uint.a open.a stralloc.a unix.a socket.a buffer.a libowfat.a
+all: t byte.a fmt.a scan.a str.a uint.a open.a stralloc.a unix.a socket.a buffer.a mmap.a libowfat.a
 
-VPATH=str:byte:fmt:scan:uint:open:stralloc:unix:socket:buffer
+VPATH=str:byte:fmt:scan:uint:open:stralloc:unix:socket:buffer:mmap
 
 CC=egcc
 #CFLAGS=-I. -pipe -Wall -Os -march=pentiumpro -fomit-frame-pointer -fschedule-insns2 -Wall
@@ -18,6 +18,7 @@ STRA_OBJS=$(patsubst stralloc/%.c,%.o,$(wildcard stralloc/*.c))
 UNIX_OBJS=$(patsubst unix/%.c,%.o,$(wildcard unix/*.c))
 SOCKET_OBJS=$(patsubst socket/%.c,%.o,$(wildcard socket/*.c))
 BUFFER_OBJS=$(patsubst buffer/%.c,%.o,$(wildcard buffer/*.c))
+MMAP_OBJS=$(patsubst mmap/%.c,%.o,$(wildcard mmap/*.c))
 
 $(BYTE_OBJS): byte.h
 $(FMT_OBJS): fmt.h
@@ -27,6 +28,7 @@ $(UINT_OBJS): uint16.h uint32.h
 $(STRA_OBJS): stralloc.h
 $(SOCKET_OBJS): socket.h
 $(BUFFER_OBJS): buffer.h
+$(MMAP_OBJS): mmap.h
 
 byte.a: $(BYTE_OBJS)
 fmt.a: $(FMT_OBJS)
@@ -38,16 +40,17 @@ stralloc.a: $(STRA_OBJS)
 unix.a: $(UNIX_OBJS)
 socket.a: $(SOCKET_OBJS)
 buffer.a: $(BUFFER_OBJS)
+mmap.a: $(MMAP_OBJS)
 
 libowfat.a: $(BYTE_OBJS) $(FMT_OBJS) $(SCAN_OBJS) $(STR_OBJS) \
 $(UINT_OBJS) $(OPEN_OBJS) $(STRA_OBJS) $(UNIX_OBJS) $(SOCKET_OBJS) \
-$(BUFFER_OBJS)
+$(BUFFER_OBJS) $(MMAP_OBJS)
 
 %.a:
 	ar cr $@ $^
 
-t: t.o socket.a stralloc.a fmt.a scan.a uint.a open.a buffer.a str.a \
-byte.a
+t: t.o socket.a stralloc.a fmt.a scan.a uint.a mmap.a open.a buffer.a \
+str.a byte.a
 	gcc -g -o $@ $^
 
 .PHONY: clean tar

mmap.h

@@ -0,0 +1,19 @@
+#ifndef MMAP_H
+#define MMAP_H
+
+#include <sys/cdefs.h>
+
+/* open file for reading, mmap whole file, close file, write length of
+ * map in filesize and return pointer to map. */
+extern char* mmap_read(const char *filename,unsigned long* filesize) __THROW;
+
+/* open file for writing, mmap whole file privately (copy on write),
+ * close file, write length of map in filesize and return pointer to
+ * map. */
+extern int mmap_write(const char *filename,unsigned long* filesize) __THROW;
+
+/* open file for writing, mmap whole file shared, close file, write
+ * length of map in filesize and return pointer to map. */
+extern int mmap_shared(const char *filename,unsigned long* filesize) __THROW;
+
+#endif

mmap/mmap_private.c

@@ -0,0 +1,19 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include "open.h"
+#include "mmap.h"
+
+extern char* mmap_private(const char* filename,unsigned long* filesize) {
+  int fd=open_read(filename);
+  char *map;
+  if (fd>=0) {
+    *filesize=lseek(fd,0,SEEK_END);
+    map=mmap(0,*filesize,PROT_WRITE,MAP_PRIVATE,fd,0);
+    if (map==(char*)-1)
+      map=0;
+    close(fd);
+    return map;
+  }
+  return 0;
+}

mmap/mmap_read.c

@@ -0,0 +1,19 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include "open.h"
+#include "mmap.h"
+
+extern char* mmap_read(const char* filename,unsigned long* filesize) {
+  int fd=open_read(filename);
+  char *map;
+  if (fd>=0) {
+    *filesize=lseek(fd,0,SEEK_END);
+    map=mmap(0,*filesize,PROT_READ,MAP_SHARED,fd,0);
+    if (map==(char*)-1)
+      map=0;
+    close(fd);
+    return map;
+  }
+  return 0;
+}

mmap/mmap_shared.c

@@ -0,0 +1,19 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include "open.h"
+#include "mmap.h"
+
+extern char* mmap_private(const char* filename,unsigned long* filesize) {
+  int fd=open_read(filename);
+  char *map;
+  if (fd>=0) {
+    *filesize=lseek(fd,0,SEEK_END);
+    map=mmap(0,*filesize,PROT_WRITE,MAP_SHARED,fd,0);
+    if (map==(char*)-1)
+      map=0;
+    close(fd);
+    return map;
+  }
+  return 0;
+}

t.c

@@ -7,15 +7,21 @@
 #include "socket.h"
 #include "buffer.h"
 #include "ip4.h"
+#include "mmap.h"
 #include <stdio.h>
 
 #define rdtscl(low) \
      __asm__ __volatile__ ("rdtsc" : "=a" (low) : : "edx")
 
 int main(int argc,char* argv[]) {
+  unsigned long len;
+  char *c=mmap_read("/etc/passwd",&len);
+  printf("got map %p of len %lu\n",c,len);
+#if 0
   char c;
   printf("%d\n",buffer_getc(buffer_0,&c));
   printf("%c\n",c);
+#endif
 #if 0
   char buf[100]="01234567890123456789012345678901234567890123456789";
   long a,b,c;