Cleanup: add lttng_/lttng-/LTTNG_ prefixes

[lttng-ust.git] / liblttng-ust / lttng-context.c

diff --git a/liblttng-ust/lttng-context.c b/liblttng-ust/lttng-context.c
new file mode 100644 (file)
index 0000000..16894ec
--- /dev/null
+++ b/liblttng-ust/lttng-context.c
@@ -0,0 +1,101 @@
+/*
+ * lttng-context.c
+ *
+ * LTTng UST trace/channel/event context management.
+ *
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+#include <lttng/ust-events.h>
+#include <lttng/ust-tracer.h>
+#include <helper.h>
+#include <string.h>
+#include <assert.h>
+
+int lttng_find_context(struct lttng_ctx *ctx, const char *name)
+{
+       unsigned int i;
+
+       for (i = 0; i < ctx->nr_fields; i++) {
+               /* Skip allocated (but non-initialized) contexts */
+               if (!ctx->fields[i].event_field.name)
+                       continue;
+               if (!strcmp(ctx->fields[i].event_field.name, name))
+                       return 1;
+       }
+       return 0;
+}
+
+/*
+ * Note: as we append context information, the pointer location may change.
+ */
+struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
+{
+       struct lttng_ctx_field *field;
+       struct lttng_ctx *ctx;
+
+       if (!*ctx_p) {
+               *ctx_p = zmalloc(sizeof(struct lttng_ctx));
+               if (!*ctx_p)
+                       return NULL;
+       }
+       ctx = *ctx_p;
+       if (ctx->nr_fields + 1 > ctx->allocated_fields) {
+               struct lttng_ctx_field *new_fields;
+
+               ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields);
+               new_fields = zmalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field));
+               if (!new_fields)
+                       return NULL;
+               if (ctx->fields)
+                       memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields);
+               free(ctx->fields);
+               ctx->fields = new_fields;
+       }
+       field = &ctx->fields[ctx->nr_fields];
+       ctx->nr_fields++;
+       return field;
+}
+
+/*
+ * Remove last context field.
+ */
+void lttng_remove_context_field(struct lttng_ctx **ctx_p,
+                               struct lttng_ctx_field *field)
+{
+       struct lttng_ctx *ctx;
+
+       ctx = *ctx_p;
+       ctx->nr_fields--;
+       assert(&ctx->fields[ctx->nr_fields] == field);
+       memset(&ctx->fields[ctx->nr_fields], 0, sizeof(struct lttng_ctx_field));
+}
+
+void lttng_destroy_context(struct lttng_ctx *ctx)
+{
+       int i;
+
+       if (!ctx)
+               return;
+       for (i = 0; i < ctx->nr_fields; i++) {
+               if (ctx->fields[i].destroy)
+                       ctx->fields[i].destroy(&ctx->fields[i]);
+       }
+       free(ctx->fields);
+       free(ctx);
+}