Changeset ff4185e6 in mainline

Timestamp:

2011-03-04T21:54:07Z (13 years ago)

Author:

Vojtech Horky <vojtechhorky@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

03f7952, f43c4d2

Parents:

019cff6

Message:

Safer and better usb_debug_str_buffer

File:

• uspace/lib/usb/src/debug.c (modified) (4 diffs)

uspace/lib/usb/src/debug.c

@@ -253 +253 @@
 
 
-#define BUFFER_DUMP_LEN 512
+#define REMAINDER_STR_FMT " (%zu)..."
+/* string + terminator + number width (enough for 4GB)*/
+#define REMAINDER_STR_LEN (5 + 1 + 10)
+#define BUFFER_DUMP_GROUP_SIZE 4
+#define BUFFER_DUMP_LEN 240 /* Ought to be enough for everybody ;-). */
 static fibril_local char buffer_dump[BUFFER_DUMP_LEN];
 
@@ -280 +284 @@
     size_t dumped_size)
 {
+        /*
+         * Remove previous string (that might also reveal double usage of
+         * this function).
+         */
+        bzero(buffer_dump, BUFFER_DUMP_LEN);
+
         if (buffer == NULL) {
                 return "(null)";
@@ -290 +300 @@
         }
 
+        /* How many bytes are available in the output buffer. */
+        size_t buffer_remaining_size = BUFFER_DUMP_LEN - 1 - REMAINDER_STR_LEN;
         char *it = buffer_dump;
 
         size_t index = 0;
 
-        while (1) {
-                /* FIXME: add range checking of the buffer size. */
-                snprintf(it, 4, "%02X ", (int) buffer[index]);
-                it += 3;
+        while (index < size) {
+                /* Determine space before the number. */
+                const char *space_before;
+                if (index == 0) {
+                        space_before = "";
+                } else if ((index % BUFFER_DUMP_GROUP_SIZE) == 0) {
+                        space_before = "  ";
+                } else {
+                        space_before = " ";
+                }
+
+                /*
+                 * Add the byte as a hexadecimal number plus the space.
+                 * We do it into temporary buffer to ensure that always
+                 * the whole byte is printed.
+                 */
+                int val = buffer[index];
+                char current_byte[16];
+                int printed = snprintf(current_byte, 16,
+                    "%s%02x", space_before, val);
+                if (printed < 0) {
+                        break;
+                }
+
+                if ((size_t) printed > buffer_remaining_size) {
+                        break;
+                }
+
+                /* We can safely add 1, because space for end 0 is reserved. */
+                str_append(it, buffer_remaining_size + 1, current_byte);
+
+                buffer_remaining_size -= printed;
+                /* Point at the terminator 0. */
+                it += printed;
                 index++;
+
                 if (index >= dumped_size) {
                         break;
@@ -304 +347 @@
         }
 
-        /* Remove the last space */
-        it--;
-        *it = 0;
+        /* Add how many bytes were not printed. */
+        if (index < size) {
+                snprintf(it, REMAINDER_STR_LEN,
+                    REMAINDER_STR_FMT, size - index);
+        }
 
         return buffer_dump;