policy extensions and age restriction refactoring

- refactoring of extension-plugin-mechanism
- refactoring of age restriction extension
- added policy extensions plugin plumbing
- added DB schema and api
  - policy_details
  - policy_fulfillments

1 files changed, 74 insertions, 26 deletions

diff --git a/src/exchangedb/exchange-0001-part.sql b/src/exchangedb/exchange-0001-part.sql
index 99883a279..4599d2ee7 100644
--- a/src/exchangedb/exchange-0001-part.sql
+++ b/src/exchangedb/exchange-0001-part.sql
@@ -411,19 +411,19 @@ COMMENT ON TABLE signkey_revocations
   IS 'Table storing which online signing keys have been revoked';
 
 
--- ------------------------------ extension ----------------------------------------
+-- ------------------------------ extensions ----------------------------------------
 
 CREATE TABLE IF NOT EXISTS extensions
   (extension_id BIGINT GENERATED BY DEFAULT AS IDENTITY UNIQUE
   ,name VARCHAR NOT NULL UNIQUE
-  ,config BYTEA
+  ,manifest BYTEA
   );
 COMMENT ON TABLE extensions
   IS 'Configurations of the activated extensions';
 COMMENT ON COLUMN extensions.name
   IS 'Name of the extension';
-COMMENT ON COLUMN extensions.config
-  IS 'Configuration of the extension as JSON-blob, maybe NULL';
+COMMENT ON COLUMN extensions.manifest
+  IS 'Manifest of the extension as JSON-blob, maybe NULL.  It contains common meta-information and extension-specific configuration.';
 
 
 -- ------------------------------ known_coins ----------------------------------------
@@ -520,21 +520,69 @@ CREATE TABLE IF NOT EXISTS refresh_transfer_keys_default
 SELECT add_constraints_to_refresh_transfer_keys_partition('default');
 
 
--- ------------------------------ extension_details ----------------------------------------
-
-CREATE TABLE IF NOT EXISTS extension_details
-  (extension_details_serial_id BIGINT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY
-  ,extension_options VARCHAR)
-  PARTITION BY HASH (extension_details_serial_id);
-COMMENT ON TABLE extension_details
-  IS 'Extensions that were provided with deposits (not yet used).';
-COMMENT ON COLUMN extension_details.extension_options
-  IS 'JSON object with options set that the exchange needs to consider when executing a deposit. Supported details depend on the extensions supported by the exchange.';
-
-CREATE TABLE IF NOT EXISTS extension_details_default
-  PARTITION OF extension_details
-  FOR VALUES WITH (MODULUS 1, REMAINDER 0);
+-- ------------------------------ policy_fulfillments -------------------------------------
 
+CREATE TABLE IF NOT EXISTS policy_fulfillments
+  (fulfillment_id BIGINT GENERATED BY DEFAULT AS IDENTITY UNIQUE PRIMARY KEY
+  ,fulfillment_timestamp INT8 NOT NULL
+  ,fulfillment_proof VARCHAR
+  ,h_fulfillment_proof BYTEA NOT NULL CHECK(LENGTH(h_fulfillment_proof) = 64) UNIQUE
+  ,policy_hash_codes BYTEA NOT NULL CHECK(0 = MOD(LENGTH(policy_hash_codes), 16))
+  );
+COMMENT ON TABLE policy_fulfillments
+  IS 'Proofs of fulfillment of policies that were set in deposits';
+COMMENT ON COLUMN policy_fulfillments.fulfillment_timestamp
+  IS 'Timestamp of the arrival of a proof of fulfillment';
+COMMENT ON COLUMN policy_fulfillments.fulfillment_proof
+  IS 'JSON object with a proof of the fulfillment of a policy. Supported details depend on the policy extensions supported by the exchange.';
+COMMENT ON COLUMN policy_fulfillments.h_fulfillment_proof
+  IS 'Hash of the fulfillment_proof';
+COMMENT ON COLUMN policy_fulfillments.policy_hash_codes
+  IS 'Concatenation of the policy_hash_code of all policy_details that are fulfilled by this proof';
+
+-- ------------------------------ policy_details ----------------------------------------
+
+CREATE TABLE IF NOT EXISTS policy_details
+  (policy_details_serial_id BIGINT GENERATED BY DEFAULT AS IDENTITY
+  ,policy_hash_code BYTEA PRIMARY KEY CHECK(LENGTH(policy_hash_code)=16)
+  ,policy_json VARCHAR
+  ,deadline INT8 NOT NULL
+  ,commitment_val INT8 NOT NULL
+  ,commitment_frac INT4 NOT NULL
+  ,accumulated_total_val INT8 NOT NULL
+  ,accumulated_total_frac INT4 NOT NULL
+  ,fee_val INT8 NOT NULL
+  ,fee_frac INT4 NOT NULL
+  ,transferable_val INT8 NOT NULL
+  ,transferable_frac INT8 NOT NULL
+  ,fulfillment_state smallint NOT NULL CHECK(fulfillment_state between 0 and 5)
+  ,fulfillment_id BIGINT NULL REFERENCES policy_fulfillments (fulfillment_id) ON DELETE CASCADE
+  );
+COMMENT ON TABLE policy_details
+  IS 'Policies that were provided with deposits via policy extensions.';
+COMMENT ON COLUMN policy_details.policy_hash_code
+  IS 'ID (GNUNET_HashCode) that identifies a policy.  Will be calculated by the policy extension based on the content';
+COMMENT ON COLUMN policy_details.policy_json
+  IS 'JSON object with options set that the exchange needs to consider when executing a deposit. Supported details depend on the policy extensions supported by the exchange.';
+COMMENT ON COLUMN policy_details.deadline
+  IS 'Deadline until the policy must be marked as fulfilled (maybe "forever")';
+COMMENT ON COLUMN policy_details.commitment_val
+  IS 'The amount that this policy commits to.  Invariant: commitment >= fee';
+COMMENT ON COLUMN policy_details.accumulated_total_val
+  IS 'The sum of all contributions of all deposit that reference this policy.  Invariant: The fulfilment_state must be Insufficient as long as accumulated_total < commitment';
+COMMENT ON COLUMN policy_details.fee_val
+  IS 'The fee for this policy, due when the policy is fulfilled or timed out';
+COMMENT ON COLUMN policy_details.transferable_val
+  IS 'The amount that on fulfilment or timeout will be transfered to the payto-URI''s of the corresponding deposit''s.  The policy fees must have been already deducted from it.  Invariant: fee+transferable <= accumulated_total.  The remaining amount (accumulated_total - fee - transferable) can be refreshed by the owner of the coins when the state is Timeout or Success.';
+COMMENT ON COLUMN policy_details.fulfillment_state
+  IS 'State of the fulfillment:
+       - 0 (Failure)
+       - 1 (Insufficient)
+       - 2 (Ready)
+       - 4 (Success)
+       - 5 (Timeout)';
+COMMENT ON COLUMN policy_details.fulfillment_id
+  IS 'Reference to the proof of the fulfillment of this policy, if it exists.  Invariant: If not NULL, this entry''s .hash_code MUST be part of the corresponding policy_fulfillments.policy_hash_codes array.';
 
 -- ------------------------------ deposits ----------------------------------------
 
@@ -552,10 +600,10 @@ COMMENT ON COLUMN deposits.wire_salt
   IS 'Salt used when hashing the payto://-URI to get the h_wire';
 COMMENT ON COLUMN deposits.done
   IS 'Set to TRUE once we have included this deposit in some aggregate wire transfer to the merchant';
-COMMENT ON COLUMN deposits.extension_blocked
-  IS 'True if the aggregation of the deposit is currently blocked by some extension mechanism. Used to filter out deposits that must not be processed by the canonical deposit logic.';
-COMMENT ON COLUMN deposits.extension_details_serial_id
-  IS 'References extensions table, NULL if extensions are not used';
+COMMENT ON COLUMN deposits.policy_blocked
+  IS 'True if the aggregation of the deposit is currently blocked by some policy extension mechanism. Used to filter out deposits that must not be processed by the canonical deposit logic.';
+COMMENT ON COLUMN deposits.policy_details_serial_id
+  IS 'References policy extensions table, NULL if extensions are not used';
 
 CREATE TABLE IF NOT EXISTS deposits_default
   PARTITION OF deposits
@@ -591,7 +639,7 @@ CREATE OR REPLACE FUNCTION deposits_insert_trigger()
 DECLARE
   is_ready BOOLEAN;
 BEGIN
-  is_ready  = NOT (NEW.done OR NEW.extension_blocked);
+  is_ready  = NOT (NEW.done OR NEW.policy_blocked);
 
   IF (is_ready)
   THEN
@@ -635,8 +683,8 @@ DECLARE
 DECLARE
   is_ready BOOLEAN;
 BEGIN
-  was_ready = NOT (OLD.done OR OLD.extension_blocked);
-  is_ready  = NOT (NEW.done OR NEW.extension_blocked);
+  was_ready = NOT (OLD.done OR OLD.policy_blocked);
+  is_ready  = NOT (NEW.done OR NEW.policy_blocked);
   IF (was_ready AND NOT is_ready)
   THEN
     DELETE FROM exchange.deposits_by_ready
@@ -690,7 +738,7 @@ CREATE OR REPLACE FUNCTION deposits_delete_trigger()
 DECLARE
   was_ready BOOLEAN;
 BEGIN
-  was_ready  = NOT (OLD.done OR OLD.extension_blocked);
+  was_ready  = NOT (OLD.done OR OLD.policy_blocked);
 
   IF (was_ready)
   THEN