Add container spec registry and code_pair spec.

The registry keeps track of different containerization strategies we
have. Implemented one that relies on a pair of code objects (a fetch
and a store), which provides one aspect of the previous functionality.

src/6model/containers.c

@@ -0,0 +1,140 @@
+#define PARROT_IN_EXTENSION
+#include "parrot/parrot.h"
+#include "parrot/extend.h"
+#include "sixmodelobject.h"
+
+/* ***************************************************************************
+ * CodePair container configuration: container with FETCH/STORE code refs
+ * ***************************************************************************/
+
+typedef struct {
+    PMC *fetch_code;
+    PMC *store_code;
+} CodePairContData;
+
+static PMC * code_pair_fetch(PARROT_INTERP, PMC *cont) {
+    CodePairContData *data = (CodePairContData *)STABLE(cont)->container_data;
+    PMC *old_ctx = Parrot_pcc_get_signature(interp, CURRENT_CONTEXT(interp));
+    PMC *cappy   = Parrot_pmc_new(interp, enum_class_CallContext);
+    VTABLE_push_pmc(interp, cappy, cont);
+    Parrot_pcc_invoke_from_sig_object(interp, data->fetch_code, cappy);
+    cappy = Parrot_pcc_get_signature(interp, CURRENT_CONTEXT(interp));
+    Parrot_pcc_set_signature(interp, CURRENT_CONTEXT(interp), old_ctx);
+    return VTABLE_get_pmc_keyed_int(interp, cappy, 0);
+}
+
+static void code_pair_store(PARROT_INTERP, PMC *cont, PMC *value) {
+    CodePairContData *data = (CodePairContData *)STABLE(cont)->container_data;
+    PMC *old_ctx = Parrot_pcc_get_signature(interp, CURRENT_CONTEXT(interp));
+    PMC *cappy   = Parrot_pmc_new(interp, enum_class_CallContext);
+    VTABLE_push_pmc(interp, cappy, cont);
+    VTABLE_push_pmc(interp, cappy, value);
+    Parrot_pcc_invoke_from_sig_object(interp, data->store_code, cappy);
+    Parrot_pcc_set_signature(interp, CURRENT_CONTEXT(interp), old_ctx);
+}
+
+static void code_pair_gc_mark_data(PARROT_INTERP, STable *st) {
+    CodePairContData *data = (CodePairContData *)st->container_data;
+    Parrot_gc_mark_PMC_alive(interp, data->fetch_code);
+    Parrot_gc_mark_PMC_alive(interp, data->store_code);
+}
+
+static void code_pair_gc_mem_sys_free_data(PARROT_INTERP, STable *st) {
+    if (st->container_data) {
+        mem_sys_free(st->container_data);
+        st->container_data = NULL;
+    }
+}
+
+static void code_pair_serialize(PARROT_INTERP, STable *st, SerializationWriter *writer) {
+    CodePairContData *data = (CodePairContData *)st->container_data;
+    writer->write_ref(interp, writer, data->fetch_code);
+    writer->write_ref(interp, writer, data->store_code);
+}
+
+static void code_pair_deserialize(PARROT_INTERP, STable *st, SerializationReader *reader) {
+    CodePairContData *data = (CodePairContData *)st->container_data;
+    data->fetch_code = reader->read_ref(interp, reader);
+    data->store_code = reader->read_ref(interp, reader);
+}
+
+static ContainerSpec *code_pair_spec = NULL;
+
+static void code_pair_set_container_spec(PARROT_INTERP, STable *st) {
+    CodePairContData *data = mem_sys_allocate(sizeof(CodePairContData));
+    data->fetch_code = PMCNULL;
+    data->store_code = PMCNULL;
+    st->container_data = data;
+    st->container_spec = code_pair_spec;
+}
+
+static void code_pair_configure_container_spec(PARROT_INTERP, STable *st, PMC *config) {
+    CodePairContData *data = (CodePairContData *)st->container_data;
+    STRING *fetch = Parrot_str_new_constant(interp, "fetch");
+    STRING *store = Parrot_str_new_constant(interp, "store");
+    if (!VTABLE_exists_keyed_str(interp, config, fetch))
+        Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_INVALID_OPERATION,
+            "Container spec 'code_pair' must be configured with a fetch");
+    if (!VTABLE_exists_keyed_str(interp, config, store))
+        Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_INVALID_OPERATION,
+            "Container spec 'code_pair' must be configured with a store");
+    data->fetch_code = VTABLE_get_pmc_keyed_str(interp, config, fetch);
+    data->store_code = VTABLE_get_pmc_keyed_str(interp, config, store);
+}
+
+static ContainerConfigurer * initialize_code_pair_spec(PARROT_INTERP) {
+    ContainerConfigurer *cc = mem_sys_allocate(sizeof(ContainerConfigurer));
+
+    code_pair_spec = mem_sys_allocate(sizeof(ContainerSpec));
+    code_pair_spec->name = Parrot_str_new_constant(interp, "code_pair");
+    code_pair_spec->fetch = code_pair_fetch;
+    code_pair_spec->store = code_pair_store;
+    code_pair_spec->gc_mark_data = code_pair_gc_mark_data;
+    code_pair_spec->gc_mem_sys_free_data = code_pair_gc_mem_sys_free_data;
+    code_pair_spec->serialize = code_pair_serialize;
+    code_pair_spec->deserialize = code_pair_deserialize;
+
+    cc->set_container_spec = code_pair_set_container_spec;
+    cc->configure_container_spec = code_pair_configure_container_spec;
+
+    return cc;
+}
+
+/* ***************************************************************************
+ * Container registry and configuration
+ * ***************************************************************************/
+
+/* Container registry is a hash mapping names of container configurations
+ * to function tables. */
+static PMC *container_registry = NULL;
+
+/* Adds a container configurer to the registry. */
+void SixModelObject_add_container_config(PARROT_INTERP, STRING *name,
+        ContainerConfigurer *configurer) {
+    PMC *wrapper = Parrot_pmc_new(interp, enum_class_Pointer);
+    VTABLE_set_pointer(interp, wrapper, configurer);
+    VTABLE_set_pmc_keyed_str(interp, container_registry, name, wrapper);
+}
+
+/* Gets a container configurer from the registry. */
+ContainerConfigurer * SixModelObject_get_container_config(PARROT_INTERP, STRING *name) {
+    if (VTABLE_exists_keyed_str(interp, container_registry, name))
+        return (ContainerConfigurer *)VTABLE_get_pointer(interp,
+            VTABLE_get_pmc_keyed_str(interp, container_registry, name));
+    else
+        Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_INVALID_OPERATION,
+            "No such container spec '%Ss'", name);
+}
+
+/* Does initial setup work of the container registry, including registering
+ * the various built-in container types. */
+void SixModelObject_containers_setup(PARROT_INTERP) {
+    /* Initialize registry. */
+    container_registry = Parrot_pmc_new(interp, enum_class_Hash);
+    Parrot_pmc_gc_register(interp, container_registry);
+
+    /* Add built-in configurations. */
+    SixModelObject_add_container_config(interp,
+        Parrot_str_new_constant(interp, "code_pair"),
+        initialize_code_pair_spec(interp));
+}

src/6model/containers.h

@@ -0,0 +1,4 @@
+void SixModelObject_add_container_config(PARROT_INTERP, STRING *name,
+        ContainerConfigurer *configurer);
+ContainerConfigurer * SixModelObject_get_container_config(PARROT_INTERP, STRING *name);
+void SixModelObject_containers_setup(PARROT_INTERP);

src/6model/sixmodelobject.h

@@ -57,6 +57,16 @@ typedef struct {
     void (*deserialize) (PARROT_INTERP, STable *st, SerializationReader *reader);
 } ContainerSpec;
 
+/* A container configurer knows how to attach a certain type of container
+ * to an STable and configure it. */
+typedef struct {
+    /* Sets this container spec in place for the specified STable. */ 
+    void (*set_container_spec) (PARROT_INTERP, STable *st);
+
+    /* Configures the container spec with the specified info. */
+    void (*configure_container_spec) (PARROT_INTERP, STable *st, PMC *config);
+} ContainerConfigurer;
+
 /* How do we invoke this thing? Specifies either an attribute to look at for
  * an invokable thing, or alternatively a method to call. */
 typedef struct {

src/ops/nqp.ops

@@ -10,6 +10,7 @@ BEGIN_OPS_PREAMBLE
 #include "../6model/repr_registry.h"
 #include "../6model/reprs/NFA.h"
 #include "../6model/serialization_context.h"
+#include "../6model/containers.h"
 #include "../guts/multi_dispatch.h"
 #include "../pmc/pmc_nqplexinfo.h"
 #include "pmc_sub.h"
@@ -322,6 +323,9 @@ inline op nqp_dynop_setup() :base_core {
         /* Initialize the object model. */
         SixModelObject_initialize(interp, &KnowHOW, &KnowHOWAttribute);
 
+        /* Initialize the container system. */
+        SixModelObject_containers_setup(interp);
+
         /* Initialize compiling SCs list. */
         compiling_scs = Parrot_pmc_new(interp, enum_class_ResizablePMCArray);
         Parrot_pmc_gc_register(interp, compiling_scs);

tools/build/Makefile.in

@@ -224,6 +224,7 @@ METAMODEL_SOURCE = src/6model/sixmodelobject.h src/6model/sixmodelobject.c \
                    src/6model/serialization_context.h src/6model/serialization.c \
                    src/6model/serialization.h src/guts/multi_dispatch.h \
                    src/guts/multi_dispatch.c src/6model/base64.c src/6model/base64.h \
+                   src/6model/containers.h src/6model/containers.c \
 
 METAMODEL_OBJS   = ../6model/sixmodelobject$(O) ../6model/repr_registry$(O) \
                    ../6model/knowhow_bootstrapper$(O) ../6model/reprs/KnowHOWREPR$(O) \
@@ -234,6 +235,7 @@ METAMODEL_OBJS   = ../6model/sixmodelobject$(O) ../6model/repr_registry$(O) \
                    ../6model/reprs/VMHash$(O) ../6model/reprs/VMIter$(O) \
                    ../6model/serialization_context$(O) ../6model/base64$(O) \
                    ../6model/serialization$(O) ../guts/multi_dispatch$(O) \
+                   ../6model/containers$(O) \
 
 LIBTOMMATH_BIN = $(TOM)core$(O) \
         $(TOM)_error$(O) \
@@ -797,6 +799,7 @@ $(OPS_DIR)/$(OPS)$(LOAD_EXT): $(OPS_DIR)/$(OPS_SOURCE) $(DYNPMC)
 	cd src/6model && $(CC) -c @cc_o_out@serialization$(O) -I../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) serialization.c
 	cd src/6model && $(CC) -c @cc_o_out@base64$(O) -I../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) base64.c
 	cd src/guts && $(CC) -c @cc_o_out@multi_dispatch$(O) -I../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) multi_dispatch.c
+	cd src/6model && $(CC) -c @cc_o_out@containers$(O) -I../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) containers.c
 	cd 3rdparty/sha1 && $(CC) -c @cc_o_out@sha1$(O) $(CINCLUDES) $(CFLAGS) sha1.c
 	cd $(OPS_DIR) && $(LD) @ld_out@$(OPS)$(LOAD_EXT) $(OPS)$(O) $(METAMODEL_OBJS) ../../3rdparty/sha1/sha1$(O) $(LINKARGS)