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module extension: add support for canonical name resolution (#2013)

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Before attempting to load a module, each provided resolver must be given an
opportunity to examine the name of the requested module without actually
loading it so as to canonicalize it, in case a module can be referred to by
multiple names.

Then, modules are loaded and cached by their canonical name.

JerryScript-DCO-1.0-Signed-off-by: Gabriel Schulhof gabriel.schulhof@intel.com
This commit is contained in:
Gabriel "_|Nix|_" Schulhof
2017-09-29 13:02:34 +03:00
committed by Zoltan Herczeg
parent e527e41bac
commit 6d53931055
6 changed files with 329 additions and 77 deletions
Download Patch File Download Diff File Expand all files Collapse all files
jerry-ext/include/jerryscript-ext/module.h
+30 -9
View File
@@ -30,7 +30,7 @@ typedef jerry_value_t (*jerryx_native_module_on_resolve_t) (void);
typedef struct jerryx_native_module_t
{
const jerry_char_t *name_p; /**< name of the module */
const jerryx_native_module_on_resolve_t on_resolve; /**< function that returns a new instance of the module */
const jerryx_native_module_on_resolve_t on_resolve_p; /**< function that returns a new instance of the module */
struct jerryx_native_module_t *next_p; /**< pointer to next module in the list */
} jerryx_native_module_t;
@@ -58,7 +58,7 @@ typedef struct jerryx_native_module_t
static jerryx_native_module_t _ ## module_name ## _definition = \
{ \
.name_p = (jerry_char_t *) #module_name, \
.on_resolve = (on_resolve_cb), \
.on_resolve_p = (on_resolve_cb), \
.next_p = NULL \
}; \
\
@@ -91,21 +91,42 @@ void jerryx_native_module_register (jerryx_native_module_t *module_p);
*/
void jerryx_native_module_unregister (jerryx_native_module_t *module_p);
/**
* Declare the function pointer type for canonical name resolution.
*/
typedef jerry_value_t (*jerryx_module_get_canonical_name_t) (const jerry_value_t name); /**< The name for which to
* compute the canonical
* name */
/**
* Declare the function pointer type for module resolution.
*/
typedef bool (*jerryx_module_resolve_t) (const jerry_value_t canonical_name, /**< The module's canonical name */
jerry_value_t *result); /**< The resulting module, if the function returns
* true */
/**
* Declare the structure for module resolvers.
*/
typedef struct
{
jerryx_module_get_canonical_name_t get_canonical_name_p; /**< function pointer to establish the canonical name of a
* module */
jerryx_module_resolve_t resolve_p; /**< function pointer to resolve a module */
} jerryx_module_resolver_t;
/**
* Declare the JerryScript module resolver so that it may be added to an array of jerryx_module_resolver_t items and
* thus passed to jerryx_module_resolve.
*/
bool jerryx_module_native_resolver (const jerry_char_t *name, jerry_value_t *result);
/**
* Declare the function pointer type for module resolvers.
*/
typedef bool (*jerryx_module_resolver_t) (const jerry_char_t *name, jerry_value_t *result);
extern jerryx_module_resolver_t jerryx_module_native_resolver;
/**
* Load a copy of a module into the current context using the provided module resolvers, or return one that was already
* loaded if it is found.
*/
jerry_value_t jerryx_module_resolve (const jerry_char_t *name, const jerryx_module_resolver_t *resolvers, size_t count);
jerry_value_t jerryx_module_resolve (const jerry_value_t name,
const jerryx_module_resolver_t **resolvers,
size_t count);
#endif /* !JERRYX_MODULE_H */
jerry-ext/module/module.c
+58 -20
View File
@@ -19,6 +19,7 @@
static const jerry_char_t *module_name_property_name = (jerry_char_t *) "moduleName";
static const jerry_char_t *module_not_found = (jerry_char_t *) "Module not found";
static const jerry_char_t *module_name_not_string = (jerry_char_t *) "Module name is not a string";
/**
* Create an error related to modules
@@ -31,15 +32,13 @@ static const jerry_char_t *module_not_found = (jerry_char_t *) "Module not found
static jerry_value_t
jerryx_module_create_error (jerry_error_t error_type, /**< the type of error to create */
const jerry_char_t *message, /**< the error message */
const jerry_char_t *module_name) /**< the module name */
const jerry_value_t module_name) /**< the module name */
{
jerry_value_t ret = jerry_create_error (error_type, message);
jerry_value_t property_name = jerry_create_string (module_name_property_name);
jerry_value_t property_value = jerry_create_string_from_utf8 (module_name);
jerry_release_value (jerry_set_property (ret, property_name, property_value));
jerry_release_value (jerry_set_property (ret, property_name, module_name));
jerry_release_value (property_name);
jerry_release_value (property_value);
return ret;
} /* jerryx_module_create_error */
@@ -167,26 +166,38 @@ static const jerry_char_t *on_resolve_absent = (jerry_char_t *) "Module on_resol
* section and loads one that matches the requested name, caching the result for subsequent requests using the context
* data mechanism.
*/
bool
jerryx_module_native_resolver (const jerry_char_t *name, /**< name of the module */
jerry_value_t *result) /**< [out] where to put the resulting module instance */
static bool
jerryx_resolve_native_module (const jerry_value_t canonical_name, /**< canonical name of the module */
jerry_value_t *result) /**< [out] where to put the resulting module instance */
{
const jerryx_native_module_t *module_p = NULL;
jerry_size_t name_size = jerry_get_utf8_string_size (canonical_name);
jerry_char_t name_string[name_size];
jerry_string_to_utf8_char_buffer (canonical_name, name_string, name_size);
/* Look for the module by its name in the list of module definitions. */
for (module_p = first_module_p; module_p != NULL; module_p = module_p->next_p)
{
if (module_p->name_p != NULL && !strcmp ((char *) module_p->name_p, (char *) name))
if (module_p->name_p != NULL && !strncmp ((char *) module_p->name_p, (char *) name_string, name_size))
{
/* If we find the module by its name we load it and cache it if it has an on_resolve () and complain otherwise. */
(*result) = ((module_p->on_resolve) ? module_p->on_resolve ()
: jerryx_module_create_error (JERRY_ERROR_TYPE, on_resolve_absent, name));
(*result) = ((module_p->on_resolve_p) ? module_p->on_resolve_p ()
: jerryx_module_create_error (JERRY_ERROR_TYPE,
on_resolve_absent,
canonical_name));
return true;
}
}
return false;
} /* jerryx_module_native_resolver */
} /* jerryx_resolve_native_module */
jerryx_module_resolver_t jerryx_module_native_resolver =
{
.get_canonical_name_p = NULL,
.resolve_p = jerryx_resolve_native_module
};
/**
* Resolve a single module using the module resolvers available in the section declared above and load it into the
@@ -202,29 +213,52 @@ jerryx_module_native_resolver (const jerry_char_t *name, /**< name of the module
* - an error indicating that something went wrong during the attempt to load the module.
*/
jerry_value_t
jerryx_module_resolve (const jerry_char_t *name, /**< name of the module to load */
const jerryx_module_resolver_t *resolvers_p, /**< list of resolvers */
jerryx_module_resolve (const jerry_value_t name, /**< name of the module to load */
const jerryx_module_resolver_t **resolvers_p, /**< list of resolvers */
size_t resolver_count) /**< number of resolvers in @p resolvers */
{
size_t index;
size_t canonical_names_used = 0;
jerry_value_t ret;
jerry_value_t instances = *(jerry_value_t *) jerry_get_context_data (&jerryx_module_manager);
jerry_value_t module_name = jerry_create_string_from_utf8 (name);
jerry_value_t instances;
jerry_value_t canonical_names[resolver_count];
jerry_value_t (*get_canonical_name_p) (const jerry_value_t name);
bool (*resolve_p) (const jerry_value_t canonical_name,
jerry_value_t *result);
/* Return the cached instance if present. */
if (jerryx_module_check_cache (instances, module_name, &ret))
if (!jerry_value_is_string (name))
{
ret = jerryx_module_create_error (JERRY_ERROR_COMMON, module_name_not_string, name);
goto done;
}
instances = *(jerry_value_t *) jerry_get_context_data (&jerryx_module_manager);
/**
* Establish the canonical name for the requested module. Each resolver presents its own canonical name. If one of
* the canonical names matches a cached module, it is returned as the result.
*/
for (index = 0; index < resolver_count; index++)
{
get_canonical_name_p = (resolvers_p[index] == NULL ? NULL : resolvers_p[index]->get_canonical_name_p);
canonical_names[index] = ((get_canonical_name_p == NULL) ? jerry_acquire_value (name)
: get_canonical_name_p (name));
canonical_names_used++;
if (jerryx_module_check_cache (instances, canonical_names[index], &ret))
{
goto done;
}
}
/* Try each resolver until one manages to find the module. */
for (index = 0; index < resolver_count; index++)
{
if ((*resolvers_p[index]) (name, &ret))
resolve_p = (resolvers_p[index] == NULL ? NULL : resolvers_p[index]->resolve_p);
if (resolve_p != NULL && resolve_p (canonical_names[index], &ret))
{
if (!jerry_value_has_error_flag (ret))
{
ret = jerryx_module_add_to_cache (instances, module_name, ret);
ret = jerryx_module_add_to_cache (instances, canonical_names[index], ret);
}
goto done;
}
@@ -234,6 +268,10 @@ jerryx_module_resolve (const jerry_char_t *name, /**< name of the module to load
ret = jerryx_module_create_error (JERRY_ERROR_COMMON, module_not_found, name);
done:
jerry_release_value (module_name);
/* Release the canonical names as returned by the various resolvers. */
for (index = 0; index < canonical_names_used; index++)
{
jerry_release_value (canonical_names[index]);
}
return ret;
} /* jerryx_module_resolve */