more skeleton logic for P2P operations on DB

4 files changed, 722 insertions, 39 deletions

diff --git a/src/exchangedb/drop0001.sql b/src/exchangedb/drop0001.sql
index c969286a0..60acc98a4 100644
--- a/src/exchangedb/drop0001.sql
+++ b/src/exchangedb/drop0001.sql
@@ -33,6 +33,7 @@ DROP TRIGGER IF EXISTS deposits_on_insert ON deposits;
 DROP TRIGGER IF EXISTS deposits_on_delete ON deposits;
 DROP TRIGGER IF EXISTS recoup_on_insert ON recoup;
 DROP TRIGGER IF EXISTS recoup_on_delete ON recoup;
+
 DROP TABLE IF EXISTS revolving_work_shards CASCADE;
 DROP TABLE IF EXISTS extensions CASCADE;
 DROP TABLE IF EXISTS auditors CASCADE;
@@ -85,50 +86,45 @@ DROP TABLE IF EXISTS recoup_by_reserve CASCADE;
 
 
 DROP TABLE IF EXISTS partners CASCADE;
-DROP TABLE IF EXISTS mergers CASCADE;
+DROP TABLE IF EXISTS account_merges CASCADE;
+DROP TABLE IF EXISTS purse_merges CASCADE;
 DROP TABLE IF EXISTS contracts CASCADE;
 DROP TABLE IF EXISTS history_requests CASCADE;
 DROP TABLE IF EXISTS close_requests CASCADE;
 DROP TABLE IF EXISTS purse_requests CASCADE;
 DROP TABLE IF EXISTS wads_out CASCADE;
-DROP TABLE IF EXISTS wads_out_entries CASCADE;
+DROP TABLE IF EXISTS wad_out_entries CASCADE;
 DROP TABLE IF EXISTS wads_in CASCADE;
-DROP TABLE IF EXISTS wads_in_entries CASCADE;
+DROP TABLE IF EXISTS wad_in_entries CASCADE;
 DROP TABLE IF EXISTS partner_accounts CASCADE;
 
 
 DROP FUNCTION IF EXISTS exchange_do_withdraw;
 DROP FUNCTION IF EXISTS exchange_do_withdraw_limit_check;
-
 DROP FUNCTION IF EXISTS recoup_insert_trigger;
 DROP FUNCTION IF EXISTS recoup_delete_trigger;
 DROP FUNCTION IF EXISTS deposits_by_coin_insert_trigger;
 DROP FUNCTION IF EXISTS deposits_by_coin_delete_trigger;
 DROP FUNCTION IF EXISTS reserves_out_by_reserve_insert_trigger;
 DROP FUNCTION IF EXISTS reserves_out_by_reserve_delete_trigger;
-
 DROP FUNCTION IF EXISTS exchange_do_deposit;
-
 DROP FUNCTION IF EXISTS exchange_do_melt;
-
 DROP FUNCTION IF EXISTS exchange_do_refund;
-
 DROP FUNCTION IF EXISTS exchange_do_recoup_to_coin;
-
 DROP FUNCTION IF EXISTS exchange_do_recoup_to_reserve;
-
--- FIXME: drop other stored functions!
+DROP FUNCTION IF EXISTS exchange_do_purse_deposit;
+DROP FUNCTION IF EXISTS exchange_do_purse_merge;
+DROP FUNCTION IF EXISTS exchange_do_account_merge;
+DROP FUNCTION IF EXISTS exchange_do_history_request;
+DROP FUNCTION IF EXISTS exchange_do_close_request;
 
 -- Unregister patch (partition-0001.sql)
 -- SELECT _v.unregister_patch('partition-0001');
 
 -- Drops for partition-0001.sql
 DROP FUNCTION IF EXISTS create_table_partition;
-
 DROP FUNCTION IF EXISTS create_partitions;
-
 DROP FUNCTION IF EXISTS detach_default_partitions;
-
 DROP FUNCTION IF EXISTS drop_default_partitions;
 
 
diff --git a/src/exchangedb/exchange-0001.sql b/src/exchangedb/exchange-0001.sql
index 5a4199040..5acb8995b 100644
--- a/src/exchangedb/exchange-0001.sql
+++ b/src/exchangedb/exchange-0001.sql
@@ -787,7 +787,7 @@ END $$;
 COMMENT ON FUNCTION deposits_by_coin_delete_trigger()
   IS 'Replicate deposits deletions into deposits_by_coin table.';
 
-CREATE TRIGGER deposit_on_delete
+CREATE TRIGGER deposits_on_delete
   AFTER DELETE
     ON deposits
    FOR EACH ROW EXECUTE FUNCTION deposits_by_coin_delete_trigger();
@@ -1410,10 +1410,11 @@ CREATE TABLE IF NOT EXISTS purse_requests
   ,merge_pub BYTEA NOT NULL CHECK (LENGTH(merge_pub)=32)
   ,purse_expiration INT8 NOT NULL
   ,h_contract_terms BYTEA NOT NULL CHECK (LENGTH(h_contract_terms)=64)
+  ,age_limit INT4 NOT NULL
   ,amount_with_fee_val INT8 NOT NULL
   ,amount_with_fee_frac INT4 NOT NULL
-  ,balance_val INT8 NOT NULL
-  ,balance_frac INT4 NOT NULL
+  ,balance_val INT8 NOT NULL DEFAULT (0)
+  ,balance_frac INT4 NOT NULL DEFAULT (0)
   ,purse_sig BYTEA NOT NULL CHECK(LENGTH(purse_sig)=64)
   ,PRIMARY KEY (purse_pub)
   ); -- partition by purse_pub
@@ -1432,6 +1433,9 @@ COMMENT ON COLUMN purse_requests.balance_val
 COMMENT ON COLUMN purse_requests.purse_sig
   IS 'Signature of the purse affirming the purse parameters, of type TALER_SIGNATURE_PURSE_REQUEST';
 
+-- FIXME: create purse_by_merge materialized index table
+-- for merge_pub => purse_pub mapping!
+
 
 CREATE TABLE IF NOT EXISTS purse_merges
   (purse_merge_request_serial_id BIGSERIAL -- UNIQUE
@@ -1487,6 +1491,7 @@ CREATE TABLE IF NOT EXISTS contracts
   ,purse_pub BYTEA NOT NULL CHECK (LENGTH(purse_pub)=32)
   ,pub_ckey BYTEA NOT NULL CHECK (LENGTH(pub_ckey)=32)
   ,e_contract BYTEA NOT NULL
+  ,purse_expiration INT8 NOT NULL
   ,PRIMARY KEY (purse_pub)
   ); -- partition by purse_pub
 COMMENT ON TABLE contracts
@@ -2899,5 +2904,85 @@ DELETE FROM cs_nonce_locks
 END $$;
 
 
+
+
+
+
+
+
+
+CREATE OR REPLACE FUNCTION exchange_do_purse_deposit(
+  IN in_purse_pub BYTEA,
+  IN in_amount_with_fee_val INT8,
+  IN in_amount_with_fee_frac INT4,
+  IN in_coin_pub BYTEA,
+  IN in_coin_sig BYTEA,
+  OUT out_balance_ok BOOLEAN,
+  OUT out_conflict BOOLEAN)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  -- FIXME
+END $$;
+
+
+CREATE OR REPLACE FUNCTION exchange_do_purse_merge(
+  IN in_purse_pub BYTEA,
+  IN in_merge_sig BYTEA,
+  IN in_merge_timestamp INT8,
+  IN in_partner_url VARCHAR,
+  IN in_reserve_pub BYTEA,
+  OUT out_balance_ok BOOLEAN,
+  OUT out_conflict BOOLEAN)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  -- FIXME
+END $$;
+
+
+CREATE OR REPLACE FUNCTION exchange_do_account_merge(
+  IN in_purse_pub BYTEA,
+  IN in_reserve_pub BYTEA,
+  IN in_reserve_sig BYTEA,
+  OUT out_balance_ok BOOLEAN,
+  OUT out_conflict BOOLEAN)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  -- FIXME
+END $$;
+
+
+CREATE OR REPLACE FUNCTION exchange_do_history_request(
+  IN in_reserve_pub BYTEA,
+  IN in_reserve_sig BYTEA,
+  IN in_request_timestamp INT8,
+  IN in_history_fee_val INT8,
+  IN in_history_fee_frac INT4,
+  OUT out_balance_ok BOOLEAN,
+  OUT out_conflict BOOLEAN)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  -- FIXME
+END $$;
+
+
+CREATE OR REPLACE FUNCTION exchange_do_close_request(
+  IN in_reserve_pub BYTEA,
+  IN in_reserve_sig BYTEA,
+  OUT out_final_balance_val INT8,
+  OUT out_final_balance_frac INT4,
+  OUT out_balance_ok BOOLEAN,
+  OUT out_conflict BOOLEAN)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  -- FIXME
+END $$;
+
+
+
 -- Complete transaction
 COMMIT;
diff --git a/src/exchangedb/plugin_exchangedb_postgres.c b/src/exchangedb/plugin_exchangedb_postgres.c
index 3f8716261..54bea9af9 100644
--- a/src/exchangedb/plugin_exchangedb_postgres.c
+++ b/src/exchangedb/plugin_exchangedb_postgres.c
@@ -3068,6 +3068,124 @@ prepare_statements (struct PostgresClosure *pg)
       "FROM extensions"
       "   WHERE name=$1;",
       1),
+
+    /* Used in #postgres_insert_partner() */
+    GNUNET_PQ_make_prepare (
+      "insert_partner",
+      "INSERT INTO partners"
+      "  (partner_master_pub"
+      "  ,start_date"
+      "  ,end_date"
+      "  ,wad_frequency"
+      "  ,wad_fee_val"
+      "  ,wad_fee_frac"
+      "  ,master_sig"
+      "  ,partner_base_url"
+      "  ) VALUES "
+      "  ($1, $2, $3, $4, $5, $6, $7, $8);",
+      8),
+    /* Used in #postgres_insert_contract() */
+    GNUNET_PQ_make_prepare (
+      "insert_contract",
+      "INSERT INTO contracts"
+      "  (purse_pub"
+      "  ,pub_ckey"
+      "  ,e_contract"
+      "  ,purse_expiration"
+      "  ) SELECT "
+      "  $1, $2, $3, purse_expiration"
+      "  FROM purse_requests"
+      "  WHERE purse_pub=$1;",
+      3),
+    /* Used in #postgres_select_contract */
+    GNUNET_PQ_make_prepare (
+      "select_contract",
+      "SELECT "
+      " pub_ckey"
+      ",e_contract"
+      " FROM contracts"
+      "   WHERE purse_pub=$1;",
+      1),
+    /* Used in #postgres_insert_purse_request() */
+    GNUNET_PQ_make_prepare (
+      "insert_purse_request",
+      "INSERT INTO purse_requests"
+      "  (purse_pub"
+      "  ,merge_pub"
+      "  ,purse_expiration"
+      "  ,h_contract_terms"
+      "  ,age_limit"
+      "  ,amount_with_fee_val"
+      "  ,amount_with_fee_frac"
+      "  ,purse_sig"
+      "  ) VALUES "
+      "  ($1, $2, $3, $4, $5, $6, $7, $8);",
+      7),
+    /* Used in #postgres_select_purse_request */
+    GNUNET_PQ_make_prepare (
+      "select_purse_request",
+      "SELECT "
+      " merge_pub"
+      ",purse_expiration"
+      ",h_contract_terms"
+      ",age_limit"
+      ",amount_with_fee_val"
+      ",amount_with_fee_frac"
+      ",purse_sig"
+      " FROM purse_requests"
+      " WHERE purse_pub=$1;",
+      1),
+    /* Used in #postgres_do_purse_deposit() */
+    GNUNET_PQ_make_prepare (
+      "call_purse_deposit",
+      "SELECT 1"
+      " FROM exchange_do_purse_deposit"
+      "  ($1, $2, $3, $4, $5);",
+      5),
+    /* Used in #postgres_do_purse_merge() */
+    GNUNET_PQ_make_prepare (
+      "call_purse_merge",
+      "SELECT 1"
+      " FROM exchange_do_purse_merge"
+      "  ($1, $2, $3, $4, $5);",
+      5),
+    /* Used in #postgres_select_purse_merge */
+    GNUNET_PQ_make_prepare (
+      "select_purse_merge",
+      "SELECT "
+      " reserve_pub"
+      ",purse_pub"
+      ",merge_sig"
+      ",merge_timestamp"
+      ",partner_base_url"
+      " FROM purse_merges"
+      " JOIN partners USING (partner_serial_id)"
+      " WHERE purse_pub=$1;",
+      1),
+    /* Used in #postgres_do_account_merge() */
+    GNUNET_PQ_make_prepare (
+      "call_account_merge",
+      "SELECT 1"
+      " FROM exchange_do_account_merge"
+      "  ($1, $2, $3);",
+      3),
+    /* Used in #postgres_insert_history_request() */
+    GNUNET_PQ_make_prepare (
+      "call_history_request",
+      "SELECT 1"
+      " FROM exchange_do_history_request"
+      "  ($1, $2, $3, $4, $5)",
+      5),
+    /* Used in #postgres_insert_close_request() */
+    GNUNET_PQ_make_prepare (
+      "call_account_close",
+      "SELECT "
+      " out_final_balance_val"
+      ",out_final_balance_frac"
+      " FROM exchange_do_close_request"
+      "  ($1, $2)",
+      2),
+
     GNUNET_PQ_PREPARED_STATEMENT_END
   };
 
@@ -9946,7 +10064,7 @@ struct RecoupRefreshSerialContext
   /**
    * Status code, set to #GNUNET_SYSERR on hard errors.
    */
-  int status;
+  enum GNUNET_GenericReturnValue status;
 };
 
 
@@ -10102,7 +10220,7 @@ struct ReserveClosedSerialContext
   /**
    * Status code, set to #GNUNET_SYSERR on hard errors.
    */
-  int status;
+  enum GNUNET_GenericReturnValue status;
 };
 
 
@@ -10148,7 +10266,7 @@ reserve_closed_serial_helper_cb (void *cls,
                                    &closing_fee),
       GNUNET_PQ_result_spec_end
     };
-    int ret;
+    enum GNUNET_GenericReturnValue ret;
 
     if (GNUNET_OK !=
         GNUNET_PQ_extract_result (result,
@@ -10377,7 +10495,7 @@ struct MissingWireContext
   /**
    * Set to #GNUNET_SYSERR on error.
    */
-  int status;
+  enum GNUNET_GenericReturnValue status;
 };
 
 
@@ -10737,7 +10855,7 @@ struct GetWireAccountsContext
   /**
    * Flag set to #GNUNET_OK as long as everything is fine.
    */
-  int status;
+  enum GNUNET_GenericReturnValue status;
 
 };
 
@@ -10844,7 +10962,7 @@ struct GetWireFeesContext
   /**
    * Flag set to #GNUNET_OK as long as everything is fine.
    */
-  int status;
+  enum GNUNET_GenericReturnValue status;
 
 };
 
@@ -12527,6 +12645,317 @@ postgres_get_extension_config (void *cls,
 
 
 /**
+ * Function called to store configuration data about a partner
+ * exchange that we are federated with.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param master_pub public offline signing key of the partner exchange
+ * @param start_date when does the following data start to be valid
+ * @param end_date when does the validity end (exclusive)
+ * @param wad_frequency how often do we do exchange-to-exchange settlements?
+ * @param wad_fee how much do we charge for transfers to the partner
+ * @param partner_base_url base URL of the partner exchange
+ * @param master_sig signature with our offline signing key affirming the above
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_insert_partner (void *cls,
+                         const struct TALER_MasterPublicKeyP *master_pub,
+                         struct GNUNET_TIME_Timestamp start_date,
+                         struct GNUNET_TIME_Timestamp end_date,
+                         struct GNUNET_TIME_Relative wad_frequency,
+                         const struct TALER_Amount *wad_fee,
+                         const char *partner_base_url,
+                         const struct TALER_MasterSignatureP *master_sig)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to persist an encrypted contract associated with a reserve.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub the purse the contract is associated with (must exist)
+ * @param pub_ckey ephemeral key for DH used to encrypt the contract
+ * @param econtract_size number of bytes in @a econtract
+ * @param econtract the encrypted contract
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_insert_contract (void *cls,
+                          const struct TALER_PurseContractPublicKeyP *purse_pub,
+                          const struct TALER_ContractDiffiePublicP *pub_ckey,
+                          size_t econtract_size,
+                          const void *econtract)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to retrieve an encrypted contract.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub key to lookup the contract by
+ * @param[out] pub_ckey set to the ephemeral DH used to encrypt the contract
+ * @param[out] econtract_size set to the number of bytes in @a econtract
+ * @param[out] econtract set to the encrypted contract on success, to be freed by the caller
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_select_contract (void *cls,
+                          const struct TALER_PurseContractPublicKeyP *purse_pub,
+                          struct TALER_ContractDiffiePublicP *pub_ckey,
+                          size_t *econtract_size,
+                          void **econtract)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to create a new purse with certain meta data.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub public key of the new purse
+ * @param merge_pub public key providing the merge capability
+ * @param purse_expiration time when the purse will expire
+ * @param h_contract_terms hash of the contract for the purse
+ * @param age_limit age limit to enforce for payments into the purse
+ * @param amount target amount (with fees) to be put into the purse
+ * @param purse_sig signature with @a purse_pub's private key affirming the above
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_insert_purse_request (
+  void *cls,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseMergePublicKeyP *merge_pub,
+  struct GNUNET_TIME_Timestamp purse_expiration,
+  const struct TALER_PrivateContractHashP *h_contract_terms,
+  uint32_t age_limit,
+  const struct TALER_Amount *amount,
+  const struct TALER_PurseContractSignatureP *purse_sig)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to reutrn meta data about a purse by the
+ * purse public key.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub public key of the purse
+ * @param[out] merge_pub public key representing the merge capability
+ * @param[out] purse_expiration when would an unmerged purse expire
+ * @param[out] h_contract_terms contract associated with the purse
+ * @param[out] target_amount amount to be put into the purse
+ * @param[out] balance amount put so far into the purse
+ * @param[out] purse_sig signature of the purse over the initialization data
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_select_purse_request (
+  void *cls,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  struct TALER_PurseMergePublicKeyP *merge_pub,
+  struct GNUNET_TIME_Timestamp *purse_expiration,
+  struct TALER_PrivateContractHashP *h_contract_terms,
+  struct TALER_Amount *target_amount,
+  struct TALER_Amount *balance,
+  struct TALER_PurseContractSignatureP *purse_sig)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to return meta data about a purse by the
+ * merge capability key.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param merge_pub public key representing the merge capability
+ * @param[out] purse_pub public key of the purse
+ * @param[out] purse_expiration when would an unmerged purse expire
+ * @param[out] h_contract_terms contract associated with the purse
+ * @param[out] target_amount amount to be put into the purse
+ * @param[out] balance amount put so far into the purse
+ * @param[out] purse_sig signature of the purse over the initialization data
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_select_purse_by_merge_pub (
+  void *cls,
+  const struct TALER_PurseMergePublicKeyP *merge_pub,
+  struct TALER_PurseContractPublicKeyP *purse_pub,
+  struct GNUNET_TIME_Timestamp *purse_expiration,
+  struct TALER_PrivateContractHashP *h_contract_terms,
+  struct TALER_Amount *target_amount,
+  struct TALER_Amount *balance,
+  struct TALER_PurseContractSignatureP *purse_sig)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to execute a transaction crediting
+ * a purse with @a amount from @a coin_pub. Reduces the
+ * value of @a coin_pub and increase the balance of
+ * the @a purse_pub purse. If the balance reaches the
+ * target amount and the purse has been merged, triggers
+ * the updates of the reserve/account balance.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub purse to credit
+ * @param coin_pub coin to deposit (debit)
+ * @param amount fraction of the coin's value to deposit
+ * @param coin_sig signature affirming the operation
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_do_purse_deposit (
+  void *cls,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_CoinSpendPublicKeyP *coin_pub,
+  const struct TALER_Amount *amount,
+  const struct TALER_CoinSpendSignatureP *coin_sig)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to approve merging a purse into a
+ * reserve by the respective purse merge key.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub purse to merge
+ * @param merge_sig signature affirming the merge
+ * @param merge_timestamp time of the merge
+ * @param partner_url URL of the partner exchange, can be NULL if the reserves lives with us
+ * @param reserve_pub public key of the reserve to credit
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_do_purse_merge (
+  void *cls,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseMergeSignatureP *merge_sig,
+  const struct GNUNET_TIME_Timestamp merge_timestamp,
+  const char *partner_url,
+  const struct TALER_ReservePublicKeyP *reserve_pub)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to approve merging of a purse with
+ * an account, made by the receiving account.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub public key of the purse
+ * @param[out] merge_sig set to the signature confirming the merge
+ * @param[out] merge_timestamp set to the time of the merge
+ * @param[out] partner_url set to the URL of the target exchange, or NULL if the target exchange is us. To be freed by the caller.
+ * @param[out] reserve_pub set to the public key of the reserve/account being credited
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_select_purse_merge (
+  void *cls,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  struct TALER_PurseMergeSignatureP *merge_sig,
+  struct GNUNET_TIME_Timestamp *merge_timestamp,
+  char **partner_url,
+  struct TALER_ReservePublicKeyP *reserve_pub)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to approve merging of a purse with
+ * an account, made by the receiving account.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub public key of the purse being merged
+ * @param reserve_pub public key of the account being credited
+ * @param reserve_sig signature of the account holder affirming the merge
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_do_account_merge (
+  void *cls,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_ReservePublicKeyP *reserve_pub,
+  const struct TALER_ReserveSignatureP *reserve_sig)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to persist a signature that
+ * prove that the client requested an
+ * account history.  Debits the @a history_fee from
+ * the reserve (if possible).
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param reserve_pub account that the history was requested for
+ * @param reserve_sig signature affirming the request
+ * @param request_timestamp when was the request made
+ * @param history_fee how much should the @a reserve_pub be charged for the request
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_insert_history_request (
+  void *cls,
+  const struct TALER_ReservePublicKeyP *reserve_pub,
+  const struct TALER_ReserveSignatureP *reserve_sig,
+  struct GNUNET_TIME_Absolute request_timestamp,
+  const struct TALER_Amount *history)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
+ * Function called to initiate closure of an account.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param reserve_pub public key of the account to close
+ * @param reserve_sig signature affiming that the account is to be closed
+ * @param[out] final_balance set to the final balance in the account that will be wired back to the origin account
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_insert_close_request (
+  void *cls,
+  const struct TALER_ReservePublicKeyP *reserve_pub,
+  const struct TALER_ReserveSignatureP *reserve_sig,
+  struct TALER_Amount *final_balance)
+{
+  GNUNET_break (0);
+  return GNUNET_DB_STATUS_HARD_ERROR;
+}
+
+
+/**
  * Initialize Postgres database subsystem.
  *
  * @param cls a configuration instance
@@ -12772,6 +13201,30 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
     = &postgres_set_extension_config;
   plugin->get_extension_config
     = &postgres_get_extension_config;
+  plugin->insert_partner
+    = &postgres_insert_partner;
+  plugin->insert_contract
+    = &postgres_insert_contract;
+  plugin->select_contract
+    = &postgres_select_contract;
+  plugin->insert_purse_request
+    = &postgres_insert_purse_request;
+  plugin->select_purse_request
+    = &postgres_select_purse_request;
+  plugin->select_purse_by_merge_pub
+    = &postgres_select_purse_by_merge_pub;
+  plugin->do_purse_deposit
+    = &postgres_do_purse_deposit;
+  plugin->do_purse_merge
+    = &postgres_do_purse_merge;
+  plugin->select_purse_merge
+    = &postgres_select_purse_merge;
+  plugin->do_account_merge
+    = &postgres_do_account_merge;
+  plugin->insert_history_request
+    = &postgres_insert_history_request;
+  plugin->insert_close_request
+    = &postgres_insert_close_request;
   return plugin;
 }
 
diff --git a/src/include/taler_exchangedb_plugin.h b/src/include/taler_exchangedb_plugin.h
index 074e952ea..cee509542 100644
--- a/src/include/taler_exchangedb_plugin.h
+++ b/src/include/taler_exchangedb_plugin.h
@@ -4354,6 +4354,20 @@ struct TALER_EXCHANGEDB_Plugin
                           char **config);
 
 
+  /**
+   * Function called to store configuration data about a partner
+   * exchange that we are federated with.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param master_pub public offline signing key of the partner exchange
+   * @param start_date when does the following data start to be valid
+   * @param end_date when does the validity end (exclusive)
+   * @param wad_frequency how often do we do exchange-to-exchange settlements?
+   * @param wad_fee how much do we charge for transfers to the partner
+   * @param partner_base_url base URL of the partner exchange
+   * @param master_sig signature with our offline signing key affirming the above
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
   (*insert_partner)(void *cls,
                     const struct TALER_MasterPublicKeyP *master_pub,
@@ -4365,6 +4379,16 @@ struct TALER_EXCHANGEDB_Plugin
                     const struct TALER_MasterSignatureP *master_sig);
 
 
+  /**
+   * Function called to persist an encrypted contract associated with a reserve.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param purse_pub the purse the contract is associated with (must exist)
+   * @param pub_ckey ephemeral key for DH used to encrypt the contract
+   * @param econtract_size number of bytes in @a econtract
+   * @param econtract the encrypted contract
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
   (*insert_contract)(void *cls,
                      const struct TALER_PurseContractPublicKeyP *purse_pub,
@@ -4373,6 +4397,16 @@ struct TALER_EXCHANGEDB_Plugin
                      const void *econtract);
 
 
+  /**
+   * Function called to retrieve an encrypted contract.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param purse_pub key to lookup the contract by
+   * @param[out] pub_ckey set to the ephemeral DH used to encrypt the contract
+   * @param[out] econtract_size set to the number of bytes in @a econtract
+   * @param[out] econtract set to the encrypted contract on success, to be freed by the caller
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
   (*select_contract)(void *cls,
                      const struct TALER_PurseContractPublicKeyP *purse_pub,
@@ -4381,6 +4415,19 @@ struct TALER_EXCHANGEDB_Plugin
                      void **econtract);
 
 
+  /**
+   * Function called to create a new purse with certain meta data.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param purse_pub public key of the new purse
+   * @param merge_pub public key providing the merge capability
+   * @param purse_expiration time when the purse will expire
+   * @param h_contract_terms hash of the contract for the purse
+   * @param age_limit age limit to enforce for payments into the purse
+   * @param amount target amount (with fees) to be put into the purse
+   * @param purse_sig signature with @a purse_pub's private key affirming the above
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
   (*insert_purse_request)(
     void *cls,
@@ -4388,10 +4435,25 @@ struct TALER_EXCHANGEDB_Plugin
     const struct TALER_PurseMergePublicKeyP *merge_pub,
     struct GNUNET_TIME_Timestamp purse_expiration,
     const struct TALER_PrivateContractHashP *h_contract_terms,
+    uint32_t age_limit,
     const struct TALER_Amount *amount,
     const struct TALER_PurseContractSignatureP *purse_sig);
 
 
+  /**
+   * Function called to reutrn meta data about a purse by the
+   * purse public key.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param purse_pub public key of the purse
+   * @param[out] merge_pub public key representing the merge capability
+   * @param[out] purse_expiration when would an unmerged purse expire
+   * @param[out] h_contract_terms contract associated with the purse
+   * @param[out] target_amount amount to be put into the purse
+   * @param[out] balance amount put so far into the purse
+   * @param[out] purse_sig signature of the purse over the initialization data
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
   (*select_purse_request)(
     void *cls,
@@ -4404,8 +4466,49 @@ struct TALER_EXCHANGEDB_Plugin
     struct TALER_PurseContractSignatureP *purse_sig);
 
 
+  /**
+   * Function called to return meta data about a purse by the
+   * merge capability key.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param merge_pub public key representing the merge capability
+   * @param[out] purse_pub public key of the purse
+   * @param[out] purse_expiration when would an unmerged purse expire
+   * @param[out] h_contract_terms contract associated with the purse
+   * @param[out] target_amount amount to be put into the purse
+   * @param[out] balance amount put so far into the purse
+   * @param[out] purse_sig signature of the purse over the initialization data
+   * @return transaction status code
+   */
+  enum GNUNET_DB_QueryStatus
+  (*select_purse_by_merge_pub)(
+    void *cls,
+    const struct TALER_PurseMergePublicKeyP *merge_pub,
+    struct TALER_PurseContractPublicKeyP *purse_pub,
+    struct GNUNET_TIME_Timestamp *purse_expiration,
+    struct TALER_PrivateContractHashP *h_contract_terms,
+    struct TALER_Amount *target_amount,
+    struct TALER_Amount *balance,
+    struct TALER_PurseContractSignatureP *purse_sig);
+
+
+  /**
+   * Function called to execute a transaction crediting
+   * a purse with @a amount from @a coin_pub. Reduces the
+   * value of @a coin_pub and increase the balance of
+   * the @a purse_pub purse. If the balance reaches the
+   * target amount and the purse has been merged, triggers
+   * the updates of the reserve/account balance.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param purse_pub purse to credit
+   * @param coin_pub coin to deposit (debit)
+   * @param amount fraction of the coin's value to deposit
+   * @param coin_sig signature affirming the operation
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
-  (*insert_purse_deposit)(
+  (*do_purse_deposit)(
     void *cls,
     const struct TALER_PurseContractPublicKeyP *purse_pub,
     const struct TALER_CoinSpendPublicKeyP *coin_pub,
@@ -4413,53 +4516,99 @@ struct TALER_EXCHANGEDB_Plugin
     const struct TALER_CoinSpendSignatureP *coin_sig);
 
 
+  /**
+   * Function called to approve merging a purse into a
+   * reserve by the respective purse merge key.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param purse_pub purse to merge
+   * @param merge_sig signature affirming the merge
+   * @param merge_timestamp time of the merge
+   * @param partner_url URL of the partner exchange, can be NULL if the reserves lives with us
+   * @param reserve_pub public key of the reserve to credit
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
-  (*insert_purse_merge)(
+  (*do_purse_merge)(
     void *cls,
     const struct TALER_PurseContractPublicKeyP *purse_pub,
-    const struct TALER_PurseMergePublicKeyP *merge_pub,
     const struct TALER_PurseMergeSignatureP *merge_sig,
     const struct GNUNET_TIME_Timestamp merge_timestamp,
-    uint64_t partner_serial_id,
+    const char *partner_url,
     const struct TALER_ReservePublicKeyP *reserve_pub);
 
 
+  /**
+   * Function called to approve merging of a purse with
+   * an account, made by the receiving account.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param purse_pub public key of the purse
+   * @param[out] merge_sig set to the signature confirming the merge
+   * @param[out] merge_timestamp set to the time of the merge
+   * @param[out] partner_url set to the URL of the target exchange, or NULL if the target exchange is us. To be freed by the caller.
+   * @param[out] reserve_pub set to the public key of the reserve/account being credited
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
   (*select_purse_merge)(
     void *cls,
     const struct TALER_PurseContractPublicKeyP *purse_pub,
-    struct TALER_PurseMergePublicKeyP *merge_pub,
     struct TALER_PurseMergeSignatureP *merge_sig,
     struct GNUNET_TIME_Timestamp *merge_timestamp,
-    uint64_t *partner_serial_id,
+    char **partner_url,
     struct TALER_ReservePublicKeyP *reserve_pub);
 
 
+  /**
+   * Function called to approve merging of a purse with
+   * an account, made by the receiving account.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param purse_pub public key of the purse being merged
+   * @param reserve_pub public key of the account being credited
+   * @param reserve_sig signature of the account holder affirming the merge
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
-  (*insert_account_merge)(
+  (*do_account_merge)(
     void *cls,
     const struct TALER_PurseContractPublicKeyP *purse_pub,
     const struct TALER_ReservePublicKeyP *reserve_pub,
     const struct TALER_ReserveSignatureP *reserve_sig);
 
 
-  enum GNUNET_DB_QueryStatus
-  (*select_account_merge)(
-    void *cls,
-    const struct TALER_PurseContractPublicKeyP *purse_pub,
-    struct TALER_ReservePublicKeyP *reserve_pub,
-    struct TALER_ReserveSignatureP *reserve_sig);
-
-
+  /**
+   * Function called to persist a signature that
+   * prove that the client requested an
+   * account history.  Debits the @a history_fee from
+   * the reserve (if possible).
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param reserve_pub account that the history was requested for
+   * @param reserve_sig signature affirming the request
+   * @param request_timestamp when was the request made
+   * @param history_fee how much should the @a reserve_pub be charged for the request
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
   (*insert_history_request)(
     void *cls,
     const struct TALER_ReservePublicKeyP *reserve_pub,
     const struct TALER_ReserveSignatureP *reserve_sig,
     struct GNUNET_TIME_Absolute request_timestamp,
-    const struct TALER_Amount *history);
+    const struct TALER_Amount *history_fee);
 
 
+  /**
+   * Function called to initiate closure of an account.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param reserve_pub public key of the account to close
+   * @param reserve_sig signature affiming that the account is to be closed
+   * @param[out] final_balance set to the final balance in the account that will be wired back to the origin account
+   * @return transaction status code
+   */
   enum GNUNET_DB_QueryStatus
   (*insert_close_request)(void *cls,
                           const struct TALER_ReservePublicKeyP *reserve_pub,