move source files to src/

git-svn-id: file:///home/lennart/svn/public/nss-mdns/trunk@51 0ee8848e-81ea-0310-a63a-f631d1a40d77

1 files changed, 185 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..5f89584
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,185 @@
+#include <sys/select.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+#include <fcntl.h>
+
+#include "util.h"
+
+/* Calculate the difference between the two specfified timeval
+ * timestamsps. */
+usec_t timeval_diff(const struct timeval *a, const struct timeval *b) {
+    usec_t r;
+    assert(a && b);
+
+    /* Check which whan is the earlier time and swap the two arguments if reuqired. */
+    if (timeval_cmp(a, b) < 0) {
+        const struct timeval *c;
+        c = a;
+        a = b;
+        b = c;
+    }
+
+    /* Calculate the second difference*/
+    r = ((usec_t) a->tv_sec - b->tv_sec)* 1000000;
+
+    /* Calculate the microsecond difference */
+    if (a->tv_usec > b->tv_usec)
+        r += ((usec_t) a->tv_usec - b->tv_usec);
+    else if (a->tv_usec < b->tv_usec)
+        r -= ((usec_t) b->tv_usec - a->tv_usec);
+
+    return r;
+}
+
+/* Compare the two timeval structs and return 0 when equal, negative when a < b, positive otherwse */
+int timeval_cmp(const struct timeval *a, const struct timeval *b) {
+    assert(a && b);
+
+    if (a->tv_sec < b->tv_sec)
+        return -1;
+
+    if (a->tv_sec > b->tv_sec)
+        return 1;
+
+    if (a->tv_usec < b->tv_usec)
+        return -1;
+
+    if (a->tv_usec > b->tv_usec)
+        return 1;
+
+    return 0;
+}
+
+/* Return the time difference between now and the specified timestamp */
+usec_t timeval_age(const struct timeval *tv) {
+    struct timeval now;
+    assert(tv);
+    gettimeofday(&now, NULL);
+    return timeval_diff(&now, tv);
+}
+
+/* Add the specified time inmicroseconds to the specified timeval structure */
+void timeval_add(struct timeval *tv, usec_t v) {
+    unsigned long secs;
+    assert(tv);
+    
+    secs = (v/1000000);
+    tv->tv_sec += (unsigned long) secs;
+    v -= secs*1000000;
+
+    tv->tv_usec += v;
+
+    /* Normalize */
+    while (tv->tv_usec >= 1000000) {
+        tv->tv_sec++;
+        tv->tv_usec -= 1000000;
+    }
+}
+
+int set_cloexec(int fd) {
+    int n;
+    assert(fd >= 0);
+    
+    if ((n = fcntl(fd, F_GETFD)) < 0)
+        return -1;
+
+    if (n & FD_CLOEXEC)
+        return 0;
+
+    return fcntl(fd, F_SETFD, n|FD_CLOEXEC);
+}
+
+int set_nonblock(int fd) {
+    int n;
+    assert(fd >= 0);
+
+    if ((n = fcntl(fd, F_GETFL)) < 0)
+        return -1;
+
+    if (n & O_NONBLOCK)
+        return 0;
+
+    return fcntl(fd, F_SETFL, n|O_NONBLOCK);
+}
+
+int wait_for_write(int fd, struct timeval *end) {
+    struct timeval now;
+
+    if (end)
+        gettimeofday(&now, NULL);
+    
+    for (;;) {
+        struct timeval tv;
+        fd_set fds;
+        int r;
+        
+        FD_ZERO(&fds);
+        FD_SET(fd, &fds);
+
+        if (end) {
+            if (timeval_cmp(&now, end) >= 0)
+                return 1;
+
+            tv.tv_sec = tv.tv_usec = 0;
+            timeval_add(&tv, timeval_diff(end, &now));
+        }
+
+        if ((r = select(fd+1, NULL, &fds, NULL, end ? &tv : NULL)) < 0) {
+            if (errno != EINTR) {
+                fprintf(stderr, "select() failed: %s\n", strerror(errno));
+                return -1;
+            }
+        } else if (r == 0)
+            return 1;
+        else {
+            if (FD_ISSET(fd, &fds))
+                return 0;
+        }
+
+        if (end)
+            gettimeofday(&now, NULL);
+    }
+}
+
+int wait_for_read(int fd, struct timeval *end) {
+    struct timeval now;
+
+    if (end)
+        gettimeofday(&now, NULL);
+
+    for (;;) {
+        struct timeval tv;
+        fd_set fds;
+        int r;
+        
+        FD_ZERO(&fds);
+        FD_SET(fd, &fds);
+
+        if (end) {
+            if (timeval_cmp(&now, end) >= 0)
+                return 1;
+            
+            tv.tv_sec = tv.tv_usec = 0;
+            timeval_add(&tv, timeval_diff(end, &now));
+        }
+        
+        if ((r = select(fd+1, &fds, NULL, NULL, end ? &tv : NULL)) < 0) {
+            if (errno != EINTR) {
+                fprintf(stderr, "select() failed: %s\n", strerror(errno));
+                return -1;
+            }
+        } else if (r == 0) 
+            return 1;
+        else {
+            
+            if (FD_ISSET(fd, &fds))
+                return 0;
+        }
+
+        if (end)
+            gettimeofday(&now, NULL);
+    }
+}
+