1 files changed, 106 insertions, 0 deletions
diff --git a/src/upb_context.h b/src/upb_context.h
new file mode 100644
index 0000000..4ddaed6
--- /dev/null
+++ b/src/upb_context.h
@@ -0,0 +1,106 @@
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * A context represents a namespace of proto definitions, sort of like an
+ * interpreter's symbol table.  It is empty when first constructed.  Clients
+ * add definitions to the context by supplying unserialized or serialized
+ * descriptors (as defined in descriptor.proto).
+ *
+ * Copyright (c) 2009 Joshua Haberman.  See LICENSE for details.
+ */
+
+#ifndef UPB_CONTEXT_H_
+#define UPB_CONTEXT_H_
+
+#include "upb.h"
+#include "upb_table.h"
+
+struct google_protobuf_FileDescriptorProto;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Definitions. ***************************************************************/
+
+/* The symbol table maps names to various kinds of symbols. */
+enum upb_symbol_type {
+  UPB_SYM_MESSAGE,
+  UPB_SYM_ENUM,
+  UPB_SYM_SERVICE,
+  UPB_SYM_EXTENSION
+};
+
+struct upb_symtab_entry {
+  struct upb_strtable_entry e;
+  enum upb_symbol_type type;
+  union upb_symbol_ref ref;
+};
+
+struct upb_context {
+  struct upb_strtable symtab;   /* The context's symbol table. */
+  struct upb_strtable psymtab;  /* Private symbols, for internal use. */
+  struct upb_msg *fds_msg;   /* This is in psymtab, ptr here for convenience. */
+
+  /* A list of the FileDescriptorProtos we own (from having parsed them
+   * ourselves) and must free on destruction. */
+  size_t fds_size, fds_len;
+  struct google_protobuf_FileDescriptorSet **fds;
+};
+
+/* Initializes and frees a upb_context, respectively. */
+bool upb_context_init(struct upb_context *c);
+void upb_context_free(struct upb_context *c);
+
+/* Looking up symbols. ********************************************************/
+
+/* Resolves the given symbol using the rules described in descriptor.proto,
+ * namely:
+ *
+ *    If the name starts with a '.', it is fully-qualified.  Otherwise, C++-like
+ *    scoping rules are used to find the type (i.e. first the nested types
+ *    within this message are searched, then within the parent, on up to the
+ *    root namespace).
+ *
+ * Returns NULL if the symbol has not been defined. */
+struct upb_symtab_entry *upb_context_resolve(struct upb_context *c,
+                                             struct upb_string *base,
+                                             struct upb_string *symbol);
+
+/* Find an entry in the symbol table with this exact name.  Returns NULL if no
+ * such symbol name exists. */
+struct upb_symtab_entry *upb_context_lookup(struct upb_context *c,
+                                            struct upb_string *symbol);
+
+INLINE struct upb_symtab_entry *upb_context_symbegin(struct upb_context *c) {
+  return (struct upb_symtab_entry*)upb_strtable_begin(&c->symtab);
+}
+
+INLINE struct upb_symtab_entry *upb_context_symnext(
+    struct upb_context *c, struct upb_symtab_entry *cur) {
+  return (struct upb_symtab_entry*)upb_strtable_next(&c->symtab, &cur->e);
+}
+
+/* Adding symbols. ************************************************************/
+
+/* Adds the definitions in the given file descriptor to this context.  All
+ * types that are referenced from fd must have previously been defined (or be
+ * defined in fd).  fd may not attempt to define any names that are already
+ * defined in this context.
+ *
+ * Caller retains ownership of fd, but the context will contain references to
+ * it, so it must outlive the context.
+ *
+ * upb_context_addfd only returns true or false; it does not give any hint
+ * about what happened in the case of failure.  This is because the descriptor
+ * is expected to have been validated at the time it was parsed/generated. */
+bool upb_context_addfd(struct upb_context *c,
+                       struct google_protobuf_FileDescriptorProto *fd);
+
+bool upb_context_parsefds(struct upb_context *c, struct upb_string *fds);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif  /* UPB_PARSE_H_ */