[dpdk-dev] [PATCH v2 1/2] telemetry: support array values in data objects

[Ciara Power <ciara.power@intel.com>]

Arrays and Dicts now support uint64_t, int and string
array values. Only one level of recursion supported.

Signed-off-by: Ciara Power <ciara.power@intel.com>

---
v2:
  - Added support for arrays to have container values.
  - Added support for int and string arrays within dict/array.
  - Added APIs for internal container memory management.
---
 lib/librte_telemetry/rte_telemetry.h          | 67 +++++++++++++++++++
 .../rte_telemetry_version.map                 |  4 ++
 lib/librte_telemetry/telemetry.c              | 56 ++++++++++++++++
 lib/librte_telemetry/telemetry_data.c         | 51 ++++++++++++++
 lib/librte_telemetry/telemetry_data.h         |  7 ++
 lib/librte_telemetry/telemetry_json.h         | 33 +++++++++
 6 files changed, 218 insertions(+)

diff --git a/lib/librte_telemetry/rte_telemetry.h b/lib/librte_telemetry/rte_telemetry.h
index eb7f2c917..89aff3429 100644
--- a/lib/librte_telemetry/rte_telemetry.h
+++ b/lib/librte_telemetry/rte_telemetry.h
@@ -44,6 +44,7 @@ enum rte_tel_value_type {
 	RTE_TEL_STRING_VAL, /** a string value */
 	RTE_TEL_INT_VAL,    /** a signed 32-bit int value */
 	RTE_TEL_U64_VAL,    /** an unsigned 64-bit int value */
+	RTE_TEL_CONTAINER, /** a container struct */
 };
 
 /**
@@ -134,6 +135,28 @@ __rte_experimental
 int
 rte_tel_data_add_array_u64(struct rte_tel_data *d, uint64_t x);
 
+/**
+ * Add a container to an array.
+ * The array must have been started by rte_tel_data_start_array() with
+ * RTE_TEL_CONTAINER as the type parameter. The rte_tel_data type
+ * must be an array of type u64/int/string.
+ *
+ * @param d
+ *   The data structure passed to the callback
+ * @param val
+ *   The rte_tel_data pointer to be returned in the container.
+ * @param keep
+ *   Integer value to represent if rte_tel_data memory should be freed
+ *    after use.
+ *   1 = keep, 0 = free.
+ * @return
+ *   0 on success, negative errno on error
+ */
+__rte_experimental
+int
+rte_tel_data_add_array_container(struct rte_tel_data *d,
+		struct rte_tel_data *val, int keep);
+
 /**
  * Add a string value to a dictionary.
  * The dict must have been started by rte_tel_data_start_dict().
@@ -188,6 +211,27 @@ int
 rte_tel_data_add_dict_u64(struct rte_tel_data *d,
 		const char *name, uint64_t val);
 
+/**
+ * Add a container to a dictionary.
+ * The dict must have been started by rte_tel_data_start_dict().
+ * The rte_tel_data type must be an array of type u64/int/string.
+ *
+ * @param d
+ *   The data structure passed to the callback
+ * @param val
+ *   The rte_tel_data pointer to be returned in the container.
+ * @param keep
+ *   Integer value to represent if rte_tel_data memory should be freed
+ *   after use.
+ *   1 = keep, 0 = free.
+ * @return
+ *   0 on success, negative errno on error
+ */
+__rte_experimental
+int
+rte_tel_data_add_dict_container(struct rte_tel_data *d, const char *name,
+		struct rte_tel_data *val, int keep);
+
 /**
  * This telemetry callback is used when registering a telemetry command.
  * It handles getting and formatting information to be returned to telemetry
@@ -262,4 +306,27 @@ int
 rte_telemetry_init(const char *runtime_dir, rte_cpuset_t *cpuset,
 		const char **err_str);
 
+/**
+ * @internal
+ * Get a data object with memory allocated.
+ *
+ * @return
+ *  Pointer to rte_tel_data.
+ */
+__rte_experimental
+struct rte_tel_data *
+rte_tel_data_alloc(void);
+
+/**
+ * @internal
+ * Free a data object that has memory allocated.
+ *
+ * @param data
+ *  Pointer to rte_tel_data.
+ *.
+ */
+__rte_experimental
+void
+rte_tel_data_free(struct rte_tel_data *data);
+
 #endif
diff --git a/lib/librte_telemetry/rte_telemetry_version.map b/lib/librte_telemetry/rte_telemetry_version.map
index 86433c21d..d1dbf8d58 100644
--- a/lib/librte_telemetry/rte_telemetry_version.map
+++ b/lib/librte_telemetry/rte_telemetry_version.map
@@ -1,12 +1,16 @@
 EXPERIMENTAL {
 	global:
 
+	rte_tel_data_add_array_container;
 	rte_tel_data_add_array_int;
 	rte_tel_data_add_array_string;
 	rte_tel_data_add_array_u64;
+	rte_tel_data_add_dict_container;
 	rte_tel_data_add_dict_int;
 	rte_tel_data_add_dict_string;
 	rte_tel_data_add_dict_u64;
+	rte_tel_data_alloc;
+	rte_tel_data_free;
 	rte_tel_data_start_array;
 	rte_tel_data_start_dict;
 	rte_tel_data_string;
diff --git a/lib/librte_telemetry/telemetry.c b/lib/librte_telemetry/telemetry.c
index e7e3d861d..a36f60a6c 100644
--- a/lib/librte_telemetry/telemetry.c
+++ b/lib/librte_telemetry/telemetry.c
@@ -120,6 +120,35 @@ command_help(const char *cmd __rte_unused, const char *params,
 	return 0;
 }
 
+static int
+recursive_data_json(const struct rte_tel_data *d, char *out_buf, size_t buf_len)
+{
+	size_t used = 0;
+	unsigned int i;
+
+	if (d->type != RTE_TEL_ARRAY_U64 && d->type != RTE_TEL_ARRAY_INT
+			&& d->type != RTE_TEL_ARRAY_STRING)
+		return snprintf(out_buf, buf_len, "null");
+
+	used = rte_tel_json_empty_array(out_buf, buf_len, 0);
+	if (d->type == RTE_TEL_ARRAY_U64)
+		for (i = 0; i < d->data_len; i++)
+			used = rte_tel_json_add_array_u64(out_buf,
+				buf_len, used,
+				d->data.array[i].u64val);
+	if (d->type == RTE_TEL_ARRAY_INT)
+		for (i = 0; i < d->data_len; i++)
+			used = rte_tel_json_add_array_int(out_buf,
+				buf_len, used,
+				d->data.array[i].ival);
+	if (d->type == RTE_TEL_ARRAY_STRING)
+		for (i = 0; i < d->data_len; i++)
+			used = rte_tel_json_add_array_string(out_buf,
+				buf_len, used,
+				d->data.array[i].sval);
+	return used;
+}
+
 static void
 output_json(const char *cmd, const struct rte_tel_data *d, int s)
 {
@@ -166,6 +195,20 @@ output_json(const char *cmd, const struct rte_tel_data *d, int s)
 						buf_len, used,
 						v->name, v->value.u64val);
 				break;
+			case RTE_TEL_CONTAINER:
+			{
+				char temp[buf_len];
+				const struct container *cont =
+						&v->value.container;
+				if (recursive_data_json(cont->data,
+						temp, buf_len) != 0)
+					used = rte_tel_json_add_obj_json(
+							cb_data_buf,
+							buf_len, used,
+							v->name, temp);
+				if (!cont->keep)
+					rte_tel_data_free(cont->data);
+			}
 			}
 		}
 		used += prefix_used;
@@ -174,6 +217,7 @@ output_json(const char *cmd, const struct rte_tel_data *d, int s)
 	case RTE_TEL_ARRAY_STRING:
 	case RTE_TEL_ARRAY_INT:
 	case RTE_TEL_ARRAY_U64:
+	case RTE_TEL_ARRAY_CONTAINER:
 		prefix_used = snprintf(out_buf, sizeof(out_buf), "{\"%.*s\":",
 				MAX_CMD_LEN, cmd);
 		cb_data_buf = &out_buf[prefix_used];
@@ -194,6 +238,18 @@ output_json(const char *cmd, const struct rte_tel_data *d, int s)
 				used = rte_tel_json_add_array_u64(cb_data_buf,
 						buf_len, used,
 						d->data.array[i].u64val);
+			else if (d->type == RTE_TEL_ARRAY_CONTAINER) {
+				char temp[buf_len];
+				const struct container *rec_data =
+						&d->data.array[i].container;
+				if (recursive_data_json(rec_data->data,
+						temp, buf_len) != 0)
+					used = rte_tel_json_add_array_json(
+							cb_data_buf,
+							buf_len, used, temp);
+				if (!rec_data->keep)
+					rte_tel_data_free(rec_data->data);
+			}
 		used += prefix_used;
 		used += strlcat(out_buf + used, "}", sizeof(out_buf) - used);
 		break;
diff --git a/lib/librte_telemetry/telemetry_data.c b/lib/librte_telemetry/telemetry_data.c
index f424bbd48..77b0fe09a 100644
--- a/lib/librte_telemetry/telemetry_data.c
+++ b/lib/librte_telemetry/telemetry_data.c
@@ -14,6 +14,7 @@ rte_tel_data_start_array(struct rte_tel_data *d, enum rte_tel_value_type type)
 			RTE_TEL_ARRAY_STRING, /* RTE_TEL_STRING_VAL = 0 */
 			RTE_TEL_ARRAY_INT,    /* RTE_TEL_INT_VAL = 1 */
 			RTE_TEL_ARRAY_U64,    /* RTE_TEL_u64_VAL = 2 */
+			RTE_TEL_ARRAY_CONTAINER, /* RTE_TEL_CONTAINER = 3 */
 	};
 	d->type = array_types[type];
 	d->data_len = 0;
@@ -74,6 +75,23 @@ rte_tel_data_add_array_u64(struct rte_tel_data *d, uint64_t x)
 	return 0;
 }
 
+int
+rte_tel_data_add_array_container(struct rte_tel_data *d,
+		struct rte_tel_data *val, int keep)
+{
+	if (d->type != RTE_TEL_ARRAY_CONTAINER ||
+			(val->type != RTE_TEL_ARRAY_U64
+			&& val->type != RTE_TEL_ARRAY_INT
+			&& val->type != RTE_TEL_ARRAY_STRING))
+		return -EINVAL;
+	if (d->data_len >= RTE_TEL_MAX_ARRAY_ENTRIES)
+		return -ENOSPC;
+
+	d->data.array[d->data_len].container.data = val;
+	d->data.array[d->data_len++].container.keep = !!keep;
+	return 0;
+}
+
 int
 rte_tel_data_add_dict_string(struct rte_tel_data *d, const char *name,
 		const char *val)
@@ -128,3 +146,36 @@ rte_tel_data_add_dict_u64(struct rte_tel_data *d,
 	const size_t bytes = strlcpy(e->name, name, RTE_TEL_MAX_STRING_LEN);
 	return bytes < RTE_TEL_MAX_STRING_LEN ? 0 : E2BIG;
 }
+
+int
+rte_tel_data_add_dict_container(struct rte_tel_data *d, const char *name,
+		struct rte_tel_data *val, int keep)
+{
+	struct tel_dict_entry *e = &d->data.dict[d->data_len];
+
+	if (d->type != RTE_TEL_DICT || (val->type != RTE_TEL_ARRAY_U64
+			&& val->type != RTE_TEL_ARRAY_INT
+			&& val->type != RTE_TEL_ARRAY_STRING))
+		return -EINVAL;
+	if (d->data_len >= RTE_TEL_MAX_DICT_ENTRIES)
+		return -ENOSPC;
+
+	d->data_len++;
+	e->type = RTE_TEL_CONTAINER;
+	e->value.container.data = val;
+	e->value.container.keep = !!keep;
+	const size_t bytes = strlcpy(e->name, name, RTE_TEL_MAX_STRING_LEN);
+	return bytes < RTE_TEL_MAX_STRING_LEN ? 0 : E2BIG;
+}
+
+struct rte_tel_data *
+rte_tel_data_alloc(void)
+{
+	return malloc(sizeof(struct rte_tel_data));
+}
+
+void
+rte_tel_data_free(struct rte_tel_data *data)
+{
+	free(data);
+}
diff --git a/lib/librte_telemetry/telemetry_data.h b/lib/librte_telemetry/telemetry_data.h
index ff3a371a3..adb84a09f 100644
--- a/lib/librte_telemetry/telemetry_data.h
+++ b/lib/librte_telemetry/telemetry_data.h
@@ -15,6 +15,12 @@ enum tel_container_types {
 	RTE_TEL_ARRAY_STRING, /** array of string values only */
 	RTE_TEL_ARRAY_INT,    /** array of signed, 32-bit int values */
 	RTE_TEL_ARRAY_U64,    /** array of unsigned 64-bit int values */
+	RTE_TEL_ARRAY_CONTAINER, /** array of container structs */
+};
+
+struct container {
+	struct rte_tel_data *data;
+	int keep;
 };
 
 /* each type here must have an equivalent enum in the value types enum in
@@ -25,6 +31,7 @@ union tel_value {
 	char sval[RTE_TEL_MAX_STRING_LEN];
 	int ival;
 	uint64_t u64val;
+	struct container container;
 };
 
 struct tel_dict_entry {
diff --git a/lib/librte_telemetry/telemetry_json.h b/lib/librte_telemetry/telemetry_json.h
index a2ce4899e..ad270b9b3 100644
--- a/lib/librte_telemetry/telemetry_json.h
+++ b/lib/librte_telemetry/telemetry_json.h
@@ -102,6 +102,22 @@ rte_tel_json_add_array_u64(char *buf, const int len, const int used,
 	return ret == 0 ? used : end + ret;
 }
 
+/*
+ * Add a new element with raw JSON value to the JSON array stored in the
+ * provided buffer.
+ */
+static inline int
+rte_tel_json_add_array_json(char *buf, const int len, const int used,
+		const char *str)
+{
+	int ret, end = used - 1; /* strip off final delimiter */
+	if (used <= 2) /* assume empty, since minimum is '[]' */
+		return __json_snprintf(buf, len, "[%s]", str);
+
+	ret = __json_snprintf(buf + end, len - end, ",%s]", str);
+	return ret == 0 ? used : end + ret;
+}
+
 /**
  * Add a new element with uint64_t value to the JSON object stored in the
  * provided buffer.
@@ -155,4 +171,21 @@ rte_tel_json_add_obj_str(char *buf, const int len, const int used,
 	return ret == 0 ? used : end + ret;
 }
 
+/**
+ * Add a new element with raw JSON value to the JSON object stored in the
+ * provided buffer.
+ */
+static inline int
+rte_tel_json_add_obj_json(char *buf, const int len, const int used,
+		const char *name, const char *val)
+{
+	int ret, end = used - 1;
+	if (used <= 2) /* assume empty, since minimum is '{}' */
+		return __json_snprintf(buf, len, "{\"%s\":%s}", name, val);
+
+	ret = __json_snprintf(buf + end, len - end, ",\"%s\":%s}",
+			name, val);
+	return ret == 0 ? used : end + ret;
+}
+
 #endif /*_RTE_TELEMETRY_JSON_H_*/
-- 
2.17.1