PSYC/social: use an Environment for setting variables / state operations

1 files changed, 262 insertions, 0 deletions

diff --git a/src/include/gnunet_env_lib.h b/src/include/gnunet_env_lib.h
new file mode 100644
index 000000000..5ff5c22db
--- /dev/null
+++ b/src/include/gnunet_env_lib.h
@@ -0,0 +1,262 @@
+/*
+     This file is part of GNUnet.
+     (C) 2013 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, or (at your
+     option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/** 
+ * @file include/gnunet_env_lib.h
+ * @brief Library providing operations for the @e environment of PSYC and Social messages,
+ *        and for (de)serializing variable values.
+ * @author Gabor X Toth
+ */
+
+
+/** 
+ * Possible operations on PSYC state (persistent) and transient variables (per message).
+ */
+enum GNUNET_ENV_Operator
+{ 
+  /**
+   * Set value of a transient variable.
+   */
+  GNUNET_ENV_OP_SET = ':',
+
+  /**
+   * Assign value for a persistent state variable.
+   *
+   * If an assigned value is NULL, the variable is deleted.
+   */
+  GNUNET_ENV_OP_ASSIGN = '=',
+
+  /**
+   * Augment state variable.
+   *
+   * Used for appending strings, adding numbers, and adding new items to a list or dictionary.
+   */
+  GNUNET_ENV_OP_AUGMENT = '+',
+
+  /**
+   * Diminish state variable.
+   *
+   * Used for subtracting numbers, and removing items from a list or dictionary.
+   */
+  GNUNET_ENV_OP_DIMINISH = '-',
+
+  /**
+   * Update state variable.
+   *
+   * Used for modifying a single item of a list or dictionary.
+   */
+  GNUNET_ENV_OP_UPDATE = '@',
+};
+
+
+/**
+ * PSYC variable types.
+ */
+enum GNUNET_ENV_Type
+{
+  GNUNET_ENV_TYPE_DATA = 0,
+  GNUNET_ENV_TYPE_NUMBER,
+  GNUNET_ENV_TYPE_LIST,
+  GNUNET_ENV_TYPE_DICT
+};
+
+
+/**
+ * PSYC state modifier.
+ */
+struct GNUNET_ENV_Modifier {
+  /**
+   * State operation.
+   */
+  GNUNET_ENV_Operator oper;
+
+  /**
+   * Variable name.
+   */
+  const char *name;
+
+  /**
+   * Size of @a value.
+   */
+  size_t value_size;
+
+  /**
+   * Value of variable.
+   */
+  const void *value;
+};
+
+
+/**
+ * Environment for a message.
+ *
+ * Contains modifiers.
+ */
+struct GNUNET_ENV_Environment;
+
+
+/** 
+ * Create an environment.
+ * 
+ * @return A newly allocated environment.
+ */
+struct GNUNET_ENV_Environment *
+GNUNET_ENV_environment_create ();
+
+
+/** 
+ * Add an operation on a variable to the environment.
+ *
+ * @param env The environment.
+ * @param oper Operation to perform.
+ * @param name Name of the variable.
+ * @param value_size Size of @a value.
+ * @param value Value of the variable.
+ * 
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error.
+ */
+int
+GNUNET_ENV_environment_operation (struct GNUNET_ENV_Environment *env,
+                                  enum GNUNET_ENV_Operator oper,
+                                  const char *name,
+                                  size_t value_size, const void *value);
+
+
+/** 
+ * Get all modifiers in the environment.
+ *
+ * @param env The environment.
+ * @param[out] modifiers_length Set to the number of returned modifiers.
+ * 
+ * @return Array of modifiers.
+ */
+struct GNUNET_ENV_Modifier *
+GNUNET_ENV_environment_get_modifiers (const struct GNUNET_ENV_Environment *env,
+                                      size_t *modifiers_length);
+
+
+/** 
+ * Add list of modifiers to the environment.
+ *
+ * @param env The environment.
+ * @param modifiers_length Number of @a modifiers.
+ * @param modifiers Array of modifiers to add.
+ * 
+ * @return 
+ */
+int
+GNUNET_ENV_environment_set_modifiers (const struct GNUNET_ENV_Environment *env,
+                                      size_t modifiers_length,
+                                      const struct GNUNET_ENV_Modifier *modifiers);
+
+
+/** 
+ * Destroy an environment.
+ *
+ * @param env The environment to destroy.
+ */
+void
+GNUNET_ENV_environment_destroy (struct GNUNET_ENV_Environment *env);
+
+
+/** 
+ * Get the type of variable.
+ *
+ * @param name Name of the variable.
+ * 
+ * @return Variable type.
+ */
+enum GNUNET_ENV_Type
+GNUNET_ENV_var_get_type (char *name);
+
+
+/** 
+ * Get the variable's value as an integer.
+ *
+ * @param size Size of value.
+ * @param value Raw value of variable.
+ * @param[out] number Value converted to a 64-bit integer. 
+ *
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if an error occurred (e.g. the value is invalid).
+ */
+int
+GNUNET_ENV_value_to_number (size_t size, const void *value, int64_t *number);
+
+
+/** 
+ * Get the variable's value as a list.
+ *
+ * @param size Size of value.
+ * @param value Raw value of variable.
+ * @param[out] list A newly created list holding the elements.
+ *
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if an error occurred (e.g. the value is invalid).
+ */
+int
+GNUNET_ENV_value_to_list (size_t size, const void *value, GNUNET_CONTAINER_SList **list);
+
+
+/** 
+ * Get the variable's value as a dictionary.
+ *
+ * @param size Size of value.
+ * @param value Raw value of variable.
+ * @param[out] dict A newly created hashmap holding the elements of the dictionary.
+ *
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if an error occurred (e.g. the value is invalid).
+ */
+int
+GNUNET_ENV_value_to_dict (size_t size, const void *value, GNUNET_CONTAINER_MultiHashMap **dict);
+
+
+/** 
+ * Create a PSYC variable value from an integer.
+ *
+ * @param number The number to convert.
+ * @param[out] value_size Size of returned value.
+ * 
+ * @return A newly allocated value or NULL on error.
+ */
+void *
+GNUNET_ENV_value_from_number (int64_t number, size_t *value_size);
+
+
+/** 
+ * Create a PSYC variable value from a list.
+ *
+ * @param list The list to convert.
+ * @param[out] value_size Size of returned value.
+ * 
+ * @return A newly allocated value or NULL on error.
+ */
+void *
+GNUNET_ENV_value_from_list (GNUNET_CONTAINER_SList *list, size_t *value_size);
+
+
+/** 
+ * Create a PSYC variable value from a dictionary.
+ *
+ * @param dict The dict to convert.
+ * @param[out] value_size Size of returned value.
+ * 
+ * @return A newly allocated value or NULL on error.
+ */
+void *
+GNUNET_ENV_value_from_dict (GNUNET_CONTAINER_MultiHashMap *dict, size_t *value_size);