json sub-object for file backend

src/bake-file-backend.c

@@ -19,6 +19,7 @@
 #include "bake-server.h"
 #include "bake-provider.h"
 #include "bake-backend.h"
+#include "bake-macros.h"
 
 /* bake-file-backend
  *
@@ -164,9 +165,11 @@ static int bake_file_backend_initialize(bake_provider_t    provider,
     bake_file_entry_t* new_entry = calloc(1, sizeof(*new_entry));
     new_entry->provider          = provider;
     new_entry->log_fd            = -1;
-    const char* tmp;
-    ptrdiff_t   d;
-    struct stat statbuf;
+    const char*         tmp;
+    ptrdiff_t           d;
+    struct stat         statbuf;
+    struct json_object* file_backend_json = NULL;
+    struct json_object* target_array      = NULL;
 
     if (!json_object_get_boolean(
             json_object_object_get(provider->json_cfg, "pipeline_enable"))) {
@@ -180,6 +183,15 @@ static int bake_file_backend_initialize(bake_provider_t    provider,
         return (BAKE_ERR_INVALID_ARG);
     }
 
+    CONFIG_HAS_OR_CREATE_OBJECT(provider->json_cfg, "file_backend",
+                                "file_backend", file_backend_json);
+    CONFIG_HAS_OR_CREATE_ARRAY(file_backend_json, "targets",
+                               "file_backend.targets", target_array);
+
+    /* TODO: populate tuning parameters specific to this backend; for now
+     * that's probably alignment and abt-io thread count?
+     */
+
     tmp = strrchr(path, '/');
     if (!tmp) tmp = path;
     new_entry->filename = strdup(tmp);
@@ -236,6 +248,11 @@ static int bake_file_backend_initialize(bake_provider_t    provider,
         goto error_cleanup;
     }
 
+    /* target successfully added; inject it into the json in array of
+     * targets for this backend
+     */
+    json_object_array_add(target_array, json_object_new_string(path));
+
     fprintf(stderr,
             "WARNING: Bake file backend does not yet support the following:\n");
     fprintf(stderr, "    * writes to non-zero region offsets\n");

src/bake-macros.h

@@ -31,4 +31,40 @@ static const int json_type_int64 = json_type_int;
         }                                                                  \
     } while (0)
 
+// Checks if a JSON object has a particular key and its value is of type object.
+// If the field does not exist, creates it with an empty object.
+// If the field exists but is not of type object, prints an error and return -1.
+// After a call to this macro, __out is set to the ceated/found field.
+#define CONFIG_HAS_OR_CREATE_OBJECT(__config, __key, __fullname, __out)        \
+    do {                                                                       \
+        __out = json_object_object_get(__config, __key);                       \
+        if (__out && !json_object_is_type(__out, json_type_object)) {          \
+            fprintf(stderr, "\"%s\" is in configuration but is not an object", \
+                    __fullname);                                               \
+            return -1;                                                         \
+        }                                                                      \
+        if (!__out) {                                                          \
+            __out = json_object_new_object();                                  \
+            json_object_object_add(__config, __key, __out);                    \
+        }                                                                      \
+    } while (0)
+
+// Checks if a JSON object has a particular key and its value is of type array.
+// If the field does not exist, creates it with an empty array.
+// If the field exists but is not of type object, prints an error and return -1.
+// After a call to this macro, __out is set to the ceated/found field.
+#define CONFIG_HAS_OR_CREATE_ARRAY(__config, __key, __fullname, __out)        \
+    do {                                                                      \
+        __out = json_object_object_get(__config, __key);                      \
+        if (__out && !json_object_is_type(__out, json_type_array)) {          \
+            fprintf(stderr, "\"%s\" is in configuration but is not an array", \
+                    __fullname);                                              \
+            return -1;                                                        \
+        }                                                                     \
+        if (!__out) {                                                         \
+            __out = json_object_new_array();                                  \
+            json_object_object_add(__config, __key, __out);                   \
+        }                                                                     \
+    } while (0)
+
 #endif /* __BAKE_MACROS */