Import sources from 2011-03-30 iso image

1 files changed, 137 insertions, 0 deletions

diff --git a/sys/src/cmd/replica/util.c b/sys/src/cmd/replica/util.c
new file mode 100755
index 000000000..f05b85ec7
--- /dev/null
+++ b/sys/src/cmd/replica/util.c
@@ -0,0 +1,137 @@
+#include "all.h"
+
+void*
+erealloc(void *a, int n)
+{
+	a = realloc(a, n);
+	if(a==nil)
+		sysfatal("realloc: %r");
+	return a;
+}
+
+char*
+estrdup(char *s)
+{
+	s = strdup(s);
+	if(s == nil)
+		sysfatal("strdup: %r");
+	return s;
+}
+
+void*
+emalloc(int n)
+{
+	void *a;
+
+	a = mallocz(n, 1);
+	if(a == nil)
+		sysfatal("malloc: %r");
+	return a;
+}
+
+/*
+ *	Custom allocators to avoid malloc overheads on small objects.
+ * 	We never free these.  (See below.)
+ */
+typedef struct Stringtab	Stringtab;
+struct Stringtab {
+	Stringtab *link;
+	char *str;
+};
+static Stringtab*
+taballoc(void)
+{
+	static Stringtab *t;
+	static uint nt;
+
+	if(nt == 0){
+		t = malloc(64*sizeof(Stringtab));
+		if(t == 0)
+			sysfatal("out of memory");
+		nt = 64;
+	}
+	nt--;
+	return t++;
+}
+
+static char*
+xstrdup(char *s)
+{
+	char *r;
+	int len;
+	static char *t;
+	static int nt;
+
+	len = strlen(s)+1;
+	if(len >= 8192)
+		sysfatal("strdup big string");
+
+	if(nt < len){
+		t = malloc(8192);
+		if(t == 0)
+			sysfatal("out of memory");
+		nt = 8192;
+	}
+	r = t;
+	t += len;
+	nt -= len;
+	strcpy(r, s);
+	return r;
+}
+
+/*
+ *	Return a uniquely allocated copy of a string.
+ *	Don't free these -- they stay in the table for the 
+ *	next caller who wants that particular string.
+ *	String comparison can be done with pointer comparison 
+ *	if you know both strings are atoms.
+ */
+static Stringtab *stab[1024];
+
+static uint
+hash(char *s)
+{
+	uint h;
+	uchar *p;
+
+	h = 0;
+	for(p=(uchar*)s; *p; p++)
+		h = h*37 + *p;
+	return h;
+}
+
+char*
+atom(char *str)
+{
+	uint h;
+	Stringtab *tab;
+	
+	h = hash(str) % nelem(stab);
+	for(tab=stab[h]; tab; tab=tab->link)
+		if(strcmp(str, tab->str) == 0)
+			return tab->str;
+
+	tab = taballoc();
+	tab->str = xstrdup(str);
+	tab->link = stab[h];
+	stab[h] = tab;
+	return tab->str;
+}
+
+char*
+unroot(char *path, char *root)
+{
+	int len;
+	char *s;
+
+	len = strlen(root);
+	while(len >= 1 && root[len-1]=='/')
+		len--;
+	if(strncmp(path, root, len)==0 && (path[len]=='/' || path[len]=='\0')){
+		s = path+len;
+		while(*s == '/')
+			s++;
+		return s;
+	}
+	return path;
+}