big update for the db*.nim modules; uses new db_common.nim

1 files changed, 37 insertions, 50 deletions

diff --git a/lib/impure/db_postgres.nim b/lib/impure/db_postgres.nim
index 5603d9686..802efb71f 100644
--- a/lib/impure/db_postgres.nim
+++ b/lib/impure/db_postgres.nim
@@ -62,47 +62,28 @@
 ##             "Dominik")
 import strutils, postgres
 
+import db_common
+export db_common
+
 type
   DbConn* = PPGconn   ## encapsulates a database connection
   Row* = seq[string]  ## a row of a dataset. NULL database values will be
-                       ## transformed always to the empty string.
+                      ## transformed always to the empty string.
   InstantRow* = tuple[res: PPGresult, line: int32]  ## a handle that can be
                                                     ## used to get a row's
                                                     ## column text on demand
-  EDb* = object of IOError ## exception that is raised if a database error occurs
-
-  SqlQuery* = distinct string ## an SQL query string
   SqlPrepared* = distinct string ## a identifier for the prepared queries
 
-  FDb* = object of IOEffect ## effect that denotes a database operation
-  FReadDb* = object of FDb   ## effect that denotes a read operation
-  FWriteDb* = object of FDb  ## effect that denotes a write operation
-{.deprecated: [TRow: Row, TSqlQuery: SqlQuery, TDbConn: DbConn,
+{.deprecated: [TRow: Row, TDbConn: DbConn,
               TSqlPrepared: SqlPrepared].}
 
-proc sql*(query: string): SqlQuery {.noSideEffect, inline.} =
-  ## constructs a SqlQuery from the string `query`. This is supposed to be
-  ## used as a raw-string-literal modifier:
-  ## ``sql"update user set counter = counter + 1"``
-  ##
-  ## If assertions are turned off, it does nothing. If assertions are turned
-  ## on, later versions will check the string for valid syntax.
-  result = SqlQuery(query)
-
 proc dbError*(db: DbConn) {.noreturn.} =
-  ## raises an EDb exception.
-  var e: ref EDb
+  ## raises a DbError exception.
+  var e: ref DbError
   new(e)
   e.msg = $pqErrorMessage(db)
   raise e
 
-proc dbError*(msg: string) {.noreturn.} =
-  ## raises an EDb exception with message `msg`.
-  var e: ref EDb
-  new(e)
-  e.msg = msg
-  raise e
-
 proc dbQuote*(s: string): string =
   ## DB quotes the string.
   result = "'"
@@ -127,7 +108,7 @@ proc dbFormat(formatstr: SqlQuery, args: varargs[string]): string =
       add(result, c)
 
 proc tryExec*(db: DbConn, query: SqlQuery,
-              args: varargs[string, `$`]): bool {.tags: [FReadDB, FWriteDb].} =
+              args: varargs[string, `$`]): bool {.tags: [ReadDbEffect, WriteDbEffect].} =
   ## tries to execute the query and returns true if successful, false otherwise.
   var res = pqexecParams(db, dbFormat(query, args), 0, nil, nil,
                         nil, nil, 0)
@@ -135,7 +116,8 @@ proc tryExec*(db: DbConn, query: SqlQuery,
   pqclear(res)
 
 proc tryExec*(db: DbConn, stmtName: SqlPrepared,
-              args: varargs[string, `$`]): bool {.tags: [FReadDB, FWriteDb].} =
+              args: varargs[string, `$`]): bool {.tags: [
+              ReadDbEffect, WriteDbEffect].} =
   ## tries to execute the query and returns true if successful, false otherwise.
   var arr = allocCStringArray(args)
   var res = pqexecPrepared(db, stmtName.string, int32(args.len), arr,
@@ -145,7 +127,7 @@ proc tryExec*(db: DbConn, stmtName: SqlPrepared,
   pqclear(res)
 
 proc exec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) {.
-  tags: [FReadDB, FWriteDb].} =
+  tags: [ReadDbEffect, WriteDbEffect].} =
   ## executes the query and raises EDB if not successful.
   var res = pqexecParams(db, dbFormat(query, args), 0, nil, nil,
                         nil, nil, 0)
@@ -153,7 +135,7 @@ proc exec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) {.
   pqclear(res)
 
 proc exec*(db: DbConn, stmtName: SqlPrepared,
-          args: varargs[string]) {.tags: [FReadDB, FWriteDb].} =
+          args: varargs[string]) {.tags: [ReadDbEffect, WriteDbEffect].} =
   var arr = allocCStringArray(args)
   var res = pqexecPrepared(db, stmtName.string, int32(args.len), arr,
                            nil, nil, 0)
@@ -196,7 +178,7 @@ proc setRow(res: PPGresult, r: var Row, line, cols: int32) =
       add(r[col], x)
 
 iterator fastRows*(db: DbConn, query: SqlQuery,
-                   args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
+                   args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
   ## executes the query and iterates over the result dataset. This is very
   ## fast, but potenially dangerous: If the for-loop-body executes another
   ## query, the results can be undefined. For Postgres it is safe though.
@@ -209,7 +191,7 @@ iterator fastRows*(db: DbConn, query: SqlQuery,
   pqclear(res)
 
 iterator fastRows*(db: DbConn, stmtName: SqlPrepared,
-                   args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
+                   args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
   ## executes the prepared query and iterates over the result dataset.
   var res = setupQuery(db, stmtName, args)
   var L = pqNfields(res)
@@ -221,9 +203,9 @@ iterator fastRows*(db: DbConn, stmtName: SqlPrepared,
 
 iterator instantRows*(db: DbConn, query: SqlQuery,
                       args: varargs[string, `$`]): InstantRow
-                      {.tags: [FReadDb].} =
+                      {.tags: [ReadDbEffect].} =
   ## same as fastRows but returns a handle that can be used to get column text
-  ## on demand using []. Returned handle is valid only within interator body.
+  ## on demand using []. Returned handle is valid only within iterator body.
   var res = setupQuery(db, query, args)
   for i in 0..pqNtuples(res)-1:
     yield (res: res, line: i)
@@ -231,9 +213,9 @@ iterator instantRows*(db: DbConn, query: SqlQuery,
 
 iterator instantRows*(db: DbConn, stmtName: SqlPrepared,
                       args: varargs[string, `$`]): InstantRow
-                      {.tags: [FReadDb].} =
+                      {.tags: [ReadDbEffect].} =
   ## same as fastRows but returns a handle that can be used to get column text
-  ## on demand using []. Returned handle is valid only within interator body.
+  ## on demand using []. Returned handle is valid only within iterator body.
   var res = setupQuery(db, stmtName, args)
   for i in 0..pqNtuples(res)-1:
     yield (res: res, line: i)
@@ -248,7 +230,7 @@ proc len*(row: InstantRow): int32 {.inline.} =
   pqNfields(row.res)
 
 proc getRow*(db: DbConn, query: SqlQuery,
-             args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
+             args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
   ## retrieves a single row. If the query doesn't return any rows, this proc
   ## will return a Row with empty strings for each column.
   var res = setupQuery(db, query, args)
@@ -258,7 +240,7 @@ proc getRow*(db: DbConn, query: SqlQuery,
   pqclear(res)
 
 proc getRow*(db: DbConn, stmtName: SqlPrepared,
-             args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
+             args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
   var res = setupQuery(db, stmtName, args)
   var L = pqNfields(res)
   result = newRow(L)
@@ -266,31 +248,34 @@ proc getRow*(db: DbConn, stmtName: SqlPrepared,
   pqClear(res)
 
 proc getAllRows*(db: DbConn, query: SqlQuery,
-                 args: varargs[string, `$`]): seq[Row] {.tags: [FReadDB].} =
+                 args: varargs[string, `$`]): seq[Row] {.
+                 tags: [ReadDbEffect].} =
   ## executes the query and returns the whole result dataset.
   result = @[]
   for r in fastRows(db, query, args):
     result.add(r)
 
 proc getAllRows*(db: DbConn, stmtName: SqlPrepared,
-                 args: varargs[string, `$`]): seq[Row] {.tags: [FReadDB].} =
+                 args: varargs[string, `$`]): seq[Row] {.tags:
+                 [ReadDbEffect].} =
   ## executes the prepared query and returns the whole result dataset.
   result = @[]
   for r in fastRows(db, stmtName, args):
     result.add(r)
 
 iterator rows*(db: DbConn, query: SqlQuery,
-               args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
+               args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
   ## same as `fastRows`, but slower and safe.
   for r in items(getAllRows(db, query, args)): yield r
 
 iterator rows*(db: DbConn, stmtName: SqlPrepared,
-               args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
+               args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
   ## same as `fastRows`, but slower and safe.
   for r in items(getAllRows(db, stmtName, args)): yield r
 
 proc getValue*(db: DbConn, query: SqlQuery,
-               args: varargs[string, `$`]): string {.tags: [FReadDB].} =
+               args: varargs[string, `$`]): string {.
+               tags: [ReadDbEffect].} =
   ## executes the query and returns the first column of the first row of the
   ## result dataset. Returns "" if the dataset contains no rows or the database
   ## value is NULL.
@@ -298,7 +283,8 @@ proc getValue*(db: DbConn, query: SqlQuery,
   result = if isNil(x): "" else: $x
 
 proc tryInsertID*(db: DbConn, query: SqlQuery,
-                  args: varargs[string, `$`]): int64  {.tags: [FWriteDb].}=
+                  args: varargs[string, `$`]): int64 {.
+                  tags: [WriteDbEffect].}=
   ## executes the query (typically "INSERT") and returns the
   ## generated ID for the row or -1 in case of an error. For Postgre this adds
   ## ``RETURNING id`` to the query, so it only works if your primary key is
@@ -311,7 +297,8 @@ proc tryInsertID*(db: DbConn, query: SqlQuery,
     result = -1
 
 proc insertID*(db: DbConn, query: SqlQuery,
-               args: varargs[string, `$`]): int64 {.tags: [FWriteDb].} =
+               args: varargs[string, `$`]): int64 {.
+               tags: [WriteDbEffect].} =
   ## executes the query (typically "INSERT") and returns the
   ## generated ID for the row. For Postgre this adds
   ## ``RETURNING id`` to the query, so it only works if your primary key is
@@ -321,7 +308,7 @@ proc insertID*(db: DbConn, query: SqlQuery,
 
 proc execAffectedRows*(db: DbConn, query: SqlQuery,
                        args: varargs[string, `$`]): int64 {.tags: [
-                       FReadDB, FWriteDb].} =
+                       ReadDbEffect, WriteDbEffect].} =
   ## executes the query (typically "UPDATE") and returns the
   ## number of affected rows.
   var q = dbFormat(query, args)
@@ -332,7 +319,7 @@ proc execAffectedRows*(db: DbConn, query: SqlQuery,
 
 proc execAffectedRows*(db: DbConn, stmtName: SqlPrepared,
                        args: varargs[string, `$`]): int64 {.tags: [
-                       FReadDB, FWriteDb].} =
+                       ReadDbEffect, WriteDbEffect].} =
   ## executes the query (typically "UPDATE") and returns the
   ## number of affected rows.
   var arr = allocCStringArray(args)
@@ -343,12 +330,12 @@ proc execAffectedRows*(db: DbConn, stmtName: SqlPrepared,
   result = parseBiggestInt($pqcmdTuples(res))
   pqclear(res)
 
-proc close*(db: DbConn) {.tags: [FDb].} =
+proc close*(db: DbConn) {.tags: [DbEffect].} =
   ## closes the database connection.
   if db != nil: pqfinish(db)
 
 proc open*(connection, user, password, database: string): DbConn {.
-  tags: [FDb].} =
+  tags: [DbEffect].} =
   ## opens a database connection. Raises `EDb` if the connection could not
   ## be established.
   ##
@@ -370,7 +357,7 @@ proc open*(connection, user, password, database: string): DbConn {.
   if pqStatus(result) != CONNECTION_OK: dbError(result) # result = nil
 
 proc setEncoding*(connection: DbConn, encoding: string): bool {.
-  tags: [FDb].} =
+  tags: [DbEffect].} =
   ## sets the encoding of a database connection, returns true for
   ## success, false for failure.
   return pqsetClientEncoding(connection, encoding) == 0