X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Fltt-context.c;fp=liblttng-ust%2Fltt-context.c;h=90747a5592f5e14a5322fb3485067acc1cfa5bdd;hb=69400ac4a4e6575f749c6326df7c2a2c8ac3bdc5;hp=0000000000000000000000000000000000000000;hpb=f3049ad9e7b72287888452b9ed542c0f36e6eefe;p=ust.git

diff --git a/liblttng-ust/ltt-context.c b/liblttng-ust/ltt-context.c
new file mode 100644
index 0000000..90747a5
--- /dev/null
+++ b/liblttng-ust/ltt-context.c
@@ -0,0 +1,88 @@
+/*
+ * ltt-context.c
+ *
+ * Copyright 2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng UST trace/channel/event context management.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <lttng/ust-events.h>
+#include <lttng/ust-tracer.h>
+#include <lttng/core.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);
+}