Changeset 4338f97 for lib

Timestamp:

02/25/15 14:57:20 (6 years ago)

Author:

Richard Sanger <rsangerarj@…>

Branches:

4.0.1-hotfixes, cachetimestamps, develop, dpdk-ndag, etsilive, libtrace4, master, ndag_format, pfring, rc-4.0.1, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance, ringtimestampfixes

Children:

2e22196d

Parents:

116f970

Message:

Check the environment variables for configuration of formats

We search for 3 environment variables and apply them to the config in the
following order. Such that the first has the lowest priority.

1. LIBTRACE_CONF, The global environment configuration
2. LIBTRACE_CONF_<FORMAT>, Applied to a given format
3. LIBTRACE_CONF_<FORMAT_URI>, Applied the specified trace

File:

• lib/trace_parallel.c (modified) (6 diffs)

lib/trace_parallel.c

@@ -100 +100 @@
 #include <signal.h>
 #include <unistd.h>
+#include <ctype.h>
 
 static inline int delay_tracetime(libtrace_t *libtrace, libtrace_packet_t *packet, libtrace_thread_t *t);
@@ -404 +405 @@
  */
 static inline int dispatch_packet(libtrace_t *trace,
-                                                 libtrace_thread_t *t,
-                                                 libtrace_packet_t **packet,
-                                                 bool tracetime) {
+                                  libtrace_thread_t *t,
+                                  libtrace_packet_t **packet,
+                                  bool tracetime) {
         if ((*packet)->error > 0) {
                 if (tracetime) {
@@ -902 +903 @@
  */
 inline static int trace_pread_packet_hasher_thread(libtrace_t *libtrace,
-                                                      libtrace_thread_t *t,
-                                                      libtrace_packet_t *packets[],
-                                                      size_t nb_packets) {
+                                                   libtrace_thread_t *t,
+                                                   libtrace_packet_t *packets[],
+                                                   size_t nb_packets) {
         size_t i;
 
@@ -1545 +1546 @@
 
         /* Figure out if we are using a dedicated hasher thread? */
-        if (require_hasher && libtrace->config.perpkt_threads > 1) {
+        if (require_hasher && libtrace->perpkt_thread_count > 1) {
                 libtrace->hasher_thread.type = THREAD_HASHER;
         }
@@ -1598 +1599 @@
 }
 
+/** Parses the environment variable LIBTRACE_CONF into the supplied
+ * configuration structure.
+ *
+ * @param libtrace The trace from which we determine the URI
+ * @param uc A configuration structure to be configured.
+ *
+ * We search for 3 environment variables and apply them to the config in the
+ * following order. Such that the first has the lowest priority.
+ *
+ * 1. LIBTRACE_CONF, The global environment configuration
+ * 2. LIBTRACE_CONF_<FORMAT>, Applied to a given format
+ * 3. LIBTRACE_CONF_<FORMAT_URI>, Applied the specified trace
+ *
+ * E.g.
+ * - int:eth0 would match LIBTRACE_CONF, LIBTRACE_CONF_INT, LIBTRACE_CONF_INT_ETH0
+ * - dag:/dev/dag0,0 would match LIBTRACE_CONF, LIBTRACE_CONF_DAG, LIBTRACE_CONF_DAG__DEV_DAG0_0
+ * - test.erf would match LIBTRACE_CONF, LIBTRACE_CONF_ERF, LIBTRACE_CONF_ERF_TEST_ERF
+ *
+ * @note All enironment variables names MUST only contian
+ * [A-Z], [0-9] and [_] (underscore) and not start with a number. Any characters
+ * outside of this range should be captilised if possible or replaced with an
+ * underscore.
+ */
+static void parse_env_config (libtrace_t *libtrace, struct user_configuration* uc) {
+        char env_name[1024] = "LIBTRACE_CONF_";
+        size_t len = strlen(env_name);
+        size_t mark = 0;
+        size_t i;
+        char * env;
+
+        /* Make our compound string */
+        strncpy(&env_name[len], libtrace->format->name, sizeof(env_name) - len);
+        len += strlen(libtrace->format->name);
+        strncpy(&env_name[len], ":", sizeof(env_name) - len);
+        len += 1;
+        strncpy(&env_name[len], libtrace->uridata, sizeof(env_name) - len);
+
+        /* env names are allowed to be A-Z (CAPS) 0-9 and _ */
+        for (i = 0; env_name[i] != 0; ++i) {
+                env_name[i] = toupper(env_name[i]);
+                if(env_name[i] == ':') {
+                        mark = i;
+                }
+                if (!( (env_name[i] >= 'A' && env_name[i] <= 'Z') ||
+                       (env_name[i] >= '0' && env_name[i] <= '9') )) {
+                        env_name[i] = '_';
+                }
+        }
+
+        /* First apply global env settings LIBTRACE_CONF */
+        env = getenv("LIBTRACE_CONF");
+        if (env)
+        {
+                printf("Got env %s", env);
+                parse_user_config(uc, env);
+        }
+
+        /* Then format settings LIBTRACE_CONF_<FORMAT> */
+        if (mark != 0) {
+                env_name[mark] = 0;
+                env = getenv(env_name);
+                if (env) {
+                        printf("Got %s=%s", env_name, env);
+                        parse_user_config(uc, env);
+                }
+                env_name[mark] = '_';
+        }
+
+        /* Finally this specific trace LIBTRACE_CONF_<FORMAT_URI> */
+        env = getenv(env_name);
+        if (env) {
+                printf("Got %s=%s", env_name, env);
+                parse_user_config(uc, env);
+        }
+}
+
 /* Start an input trace in the parallel libtrace framework.
  * This can also be used to restart an existing parallel.
@@ -1650 +1727 @@
         libtrace_parallel = 1;
 
+        /* Parses configuration passed through environment variables */
+        parse_env_config(libtrace, &libtrace->config);
         verify_configuration(libtrace);