Mercurial > urweb
diff src/postgres.sml @ 2176:d2a98983f502
Start of support for surviving database-server restarts, for Postgres
| author | Adam Chlipala <adam@chlipala.net> |
|---|---|
| date | Sat, 17 Oct 2015 10:49:25 -0400 |
| parents | 661b531f55bd |
| children | 00cf8214c2e3 |
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--- a/src/postgres.sml Thu Oct 15 07:52:37 2015 -0400 +++ b/src/postgres.sml Sat Oct 17 10:49:25 2015 -0400 @@ -1,4 +1,4 @@ -(* Copyright (c) 2008-2010, Adam Chlipala +(* Copyright (c) 2008-2010, 2015, Adam Chlipala * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -520,7 +520,7 @@ newline, string "PQfinish(conn);", newline, - string "uw_error(ctx, BOUNDED_RETRY, ", + string "uw_error(ctx, FATAL, ", string "\"Connection to Postgres server failed: %s\", msg);"], newline, string "}", @@ -612,12 +612,24 @@ getter t end -fun queryCommon {loc, query, cols, doCols} = +fun queryCommon {loc, query, cols, doCols, runit} = box [string "int n, i;", newline, newline, - string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating query result.\");", + string "if (res == NULL) {", + box [newline, + string "if (uw_try_reconnecting_if_at_most_one(ctx)) {", + box [newline, + string "conn = uw_get_db(ctx);", + newline, + runit, + newline], + string "}", + newline, + string "if (res == NULL) uw_error(ctx, FATAL, \"Can't allocate query result; database server might be down.\");", + newline], + string "}", newline, newline, @@ -687,12 +699,18 @@ newline] fun query {loc, cols, doCols} = - box [string "PGconn *conn = uw_get_db(ctx);", - newline, - string "PGresult *res = PQexecParams(conn, query, 0, NULL, NULL, NULL, NULL, 0);", - newline, - newline, - queryCommon {loc = loc, cols = cols, doCols = doCols, query = string "query"}] + let + val runit = string "res = PQexecParams(conn, query, 0, NULL, NULL, NULL, NULL, 0);" + in + box [string "PGconn *conn = uw_get_db(ctx);", + newline, + string "PGresult *res;", + newline, + runit, + newline, + newline, + queryCommon {loc = loc, cols = cols, doCols = doCols, query = string "query", runit = runit}] + end fun p_ensql t e = case t of @@ -756,33 +774,52 @@ newline] fun queryPrepared {loc, id, query, inputs, cols, doCols, nested = _} = - box [string "PGconn *conn = uw_get_db(ctx);", - newline, + let + val runit = + box [string "res = ", + if #persistent (Settings.currentProtocol ()) then + box [string "PQexecPrepared(conn, \"uw", + string (Int.toString id), + string "\", ", + string (Int.toString (length inputs)), + string ", paramValues, paramLengths, paramFormats, 0);"] + else + box [string "PQexecParams(conn, \"", + string (Prim.toCString query), + string "\", ", + string (Int.toString (length inputs)), + string ", NULL, paramValues, paramLengths, paramFormats, 0);"]] + in + box [string "PGconn *conn = uw_get_db(ctx);", + newline, + + makeParams inputs, + + newline, + string "PGresult *res;", + runit, + newline, + newline, + queryCommon {loc = loc, cols = cols, doCols = doCols, query = box [string "\"", + string (Prim.toCString query), + string "\""], + runit = runit}] + end - makeParams inputs, - - newline, - string "PGresult *res = ", - if #persistent (Settings.currentProtocol ()) then - box [string "PQexecPrepared(conn, \"uw", - string (Int.toString id), - string "\", ", - string (Int.toString (length inputs)), - string ", paramValues, paramLengths, paramFormats, 0);"] - else - box [string "PQexecParams(conn, \"", - string (Prim.toCString query), - string "\", ", - string (Int.toString (length inputs)), - string ", NULL, paramValues, paramLengths, paramFormats, 0);"], - newline, - newline, - queryCommon {loc = loc, cols = cols, doCols = doCols, query = box [string "\"", - string (Prim.toCString query), - string "\""]}] - -fun dmlCommon {loc, dml, mode} = - box [string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating DML result.\");", +fun dmlCommon {loc, dml, mode, runit} = + box [string "if (res == NULL) {", + box [newline, + string "if (uw_try_reconnecting_if_at_most_one(ctx)) {", + box [newline, + string "conn = uw_get_db(ctx);", + newline, + runit, + newline], + string "}", + newline, + string "if (res == NULL) uw_error(ctx, FATAL, \"Can't allocate DML result; database server might be down.\");", + newline], + string "}", newline, newline, @@ -818,7 +855,11 @@ string "res = PQexec(conn, \"ROLLBACK TO s\");", newline, - string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating DML result.\");", + string "if (res == NULL) {", + box [newline, + string "uw_error(ctx, FATAL, \"Can't allocate DML ROLLBACK result; database server might be down.\");", + newline], + string "}", newline, newline, @@ -851,7 +892,7 @@ newline, string "res = PQexec(conn, \"RELEASE s\");", newline, - string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating DML result.\");", + string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating DML RELEASE result.\");", newline, newline, @@ -877,7 +918,7 @@ Error => box [] | None => box [string "res = PQexec(conn, \"SAVEPOINT s\");", newline, - string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating DML result.\");", + string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating DML SAVEPOINT result.\");", newline, newline, string "if (PQresultStatus(res) != PGRES_COMMAND_OK) {", @@ -893,52 +934,71 @@ newline] fun dml (loc, mode) = - box [string "PGconn *conn = uw_get_db(ctx);", - newline, - string "PGresult *res;", - newline, + let + val runit = string "res = PQexecParams(conn, dml, 0, NULL, NULL, NULL, NULL, 0);" + in + box [string "PGconn *conn = uw_get_db(ctx);", + newline, + string "PGresult *res;", + newline, - makeSavepoint mode, + makeSavepoint mode, - string "res = PQexecParams(conn, dml, 0, NULL, NULL, NULL, NULL, 0);", - newline, - newline, - dmlCommon {loc = loc, dml = string "dml", mode = mode}] + runit, + newline, + newline, + dmlCommon {loc = loc, dml = string "dml", mode = mode, runit = runit}] + end fun dmlPrepared {loc, id, dml, inputs, mode} = - box [string "PGconn *conn = uw_get_db(ctx);", - newline, + let + val runit = + box [string "res = ", + if #persistent (Settings.currentProtocol ()) then + box [string "PQexecPrepared(conn, \"uw", + string (Int.toString id), + string "\", ", + string (Int.toString (length inputs)), + string ", paramValues, paramLengths, paramFormats, 0);"] + else + box [string "PQexecParams(conn, \"", + string (Prim.toCString dml), + string "\", ", + string (Int.toString (length inputs)), + string ", NULL, paramValues, paramLengths, paramFormats, 0);"]] + in + box [string "PGconn *conn = uw_get_db(ctx);", + newline, - makeParams inputs, + makeParams inputs, - newline, - string "PGresult *res;", - newline, - newline, + newline, + string "PGresult *res;", + newline, + newline, - makeSavepoint mode, + makeSavepoint mode, - string "res = ", - if #persistent (Settings.currentProtocol ()) then - box [string "PQexecPrepared(conn, \"uw", - string (Int.toString id), - string "\", ", - string (Int.toString (length inputs)), - string ", paramValues, paramLengths, paramFormats, 0);"] - else - box [string "PQexecParams(conn, \"", - string (Prim.toCString dml), - string "\", ", - string (Int.toString (length inputs)), - string ", NULL, paramValues, paramLengths, paramFormats, 0);"], - newline, - newline, - dmlCommon {loc = loc, dml = box [string "\"", - string (Prim.toCString dml), - string "\""], mode = mode}] + runit, + newline, + newline, + dmlCommon {loc = loc, dml = box [string "\"", + string (Prim.toCString dml), + string "\""], mode = mode, runit = runit}] + end -fun nextvalCommon {loc, query} = - box [string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating nextval result.\");", +fun nextvalCommon {loc, query, runit} = + box [string "if (res == NULL) {", + box [newline, + string "if (uw_try_reconnecting_if_at_most_one(ctx))", + newline, + string "conn = uw_get_db(ctx);", + newline, + runit, + newline, + string "uw_error(ctx, FATAL, \"Out of memory allocating nextval result.\");", + newline], + string "}", newline, newline, @@ -987,6 +1047,8 @@ | _ => box [string "uw_Basis_strcat(ctx, \"SELECT NEXTVAL('\", uw_Basis_strcat(ctx, ", seqE, string ", \"')\"))"] + + val runit = string "res = PQexecParams(conn, query, 0, NULL, NULL, NULL, NULL, 0);" in box [string "char *query = ", query, @@ -994,33 +1056,53 @@ newline, string "PGconn *conn = uw_get_db(ctx);", newline, - string "PGresult *res = PQexecParams(conn, query, 0, NULL, NULL, NULL, NULL, 0);", + string "PGresult *res;", newline, + runit, newline, - nextvalCommon {loc = loc, query = string "query"}] + newline, + nextvalCommon {loc = loc, query = string "query", runit = runit}] end fun nextvalPrepared {loc, id, query} = - box [string "PGconn *conn = uw_get_db(ctx);", - newline, - newline, - string "PGresult *res = ", - if #persistent (Settings.currentProtocol ()) then - box [string "PQexecPrepared(conn, \"uw", - string (Int.toString id), - string "\", 0, NULL, NULL, NULL, 0);"] - else - box [string "PQexecParams(conn, \"", - string (Prim.toCString query), - string "\", 0, NULL, NULL, NULL, NULL, 0);"], - newline, - newline, - nextvalCommon {loc = loc, query = box [string "\"", - string (Prim.toCString query), - string "\""]}] + let + val runit = + box [string "res = ", + if #persistent (Settings.currentProtocol ()) then + box [string "PQexecPrepared(conn, \"uw", + string (Int.toString id), + string "\", 0, NULL, NULL, NULL, 0);"] + else + box [string "PQexecParams(conn, \"", + string (Prim.toCString query), + string "\", 0, NULL, NULL, NULL, NULL, 0);"]] + in + box [string "PGconn *conn = uw_get_db(ctx);", + newline, + newline, -fun setvalCommon {loc, query} = - box [string "if (res == NULL) uw_error(ctx, FATAL, \"Out of memory allocating setval result.\");", + string "PGresult *res;", + newline, + runit, + newline, + newline, + nextvalCommon {loc = loc, query = box [string "\"", + string (Prim.toCString query), + string "\""], runit = runit}] + end + +fun setvalCommon {loc, query, runit} = + box [string "if (res == NULL) {", + box [newline, + string "if (uw_try_reconnecting_if_at_most_one(ctx))", + newline, + string "conn = uw_get_db(ctx);", + newline, + runit, + newline, + string "uw_error(ctx, FATAL, \"Out of memory allocating setval result.\");", + newline], + string "}", newline, newline, @@ -1048,6 +1130,8 @@ string ", uw_Basis_strcat(ctx, \"', \", uw_Basis_strcat(ctx, uw_Basis_sqlifyInt(ctx, ", count, string "), \")\"))))"] + + val runit = string "res = PQexecParams(conn, query, 0, NULL, NULL, NULL, NULL, 0);" in box [string "char *query = ", query, @@ -1055,10 +1139,13 @@ newline, string "PGconn *conn = uw_get_db(ctx);", newline, - string "PGresult *res = PQexecParams(conn, query, 0, NULL, NULL, NULL, NULL, 0);", + + string "PGresult *res;", newline, + runit, newline, - setvalCommon {loc = loc, query = string "query"}] + newline, + setvalCommon {loc = loc, query = string "query", runit = runit}] end fun sqlifyString s = "E'" ^ String.translate (fn #"'" => "\\'"