add basic ARCHITECTURE.md (#2503)

* refactor: move ApiRequest a top-level module
* refactor: rename DbStructure to SchemaCache
* refactor: GucHeader inside Response
* refactor: admin app to Workers
This commit is contained in:
Steve Chavez
2022-10-10 11:24:45 -05:00
committed by GitHub
parent e4b98d51be
commit 0fbb116dd2
35 changed files with 451 additions and 385 deletions
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-- |
-- Module: PostgREST.ApiRequest.Preferences
-- Description: Track client preferences to be employed when processing requests
--
-- Track client prefences set in HTTP 'Prefer' headers according to RFC7240[1].
--
-- [1] https://datatracker.ietf.org/doc/html/rfc7240
--
module PostgREST.ApiRequest.Preferences
( Preferences(..)
, PreferCount(..)
, PreferParameters(..)
, PreferRepresentation(..)
, PreferResolution(..)
, PreferTransaction(..)
, fromHeaders
, ToAppliedHeader(..)
, shouldCount
) where
import qualified Data.ByteString.Char8 as BS
import qualified Data.Map as Map
import qualified Network.HTTP.Types.Header as HTTP
import Protolude
-- $setup
-- Setup for doctests
-- >>> import Text.Pretty.Simple (pPrint)
-- >>> deriving instance Show PreferResolution
-- >>> deriving instance Show PreferRepresentation
-- >>> deriving instance Show PreferParameters
-- >>> deriving instance Show PreferCount
-- >>> deriving instance Show PreferTransaction
-- >>> deriving instance Show Preferences
-- | Preferences recognized by the application.
data Preferences
= Preferences
{ preferResolution :: Maybe PreferResolution
, preferRepresentation :: Maybe PreferRepresentation
, preferParameters :: Maybe PreferParameters
, preferCount :: Maybe PreferCount
, preferTransaction :: Maybe PreferTransaction
}
-- |
-- Parse HTTP headers based on RFC7240[1] to identify preferences.
--
-- One header with comma-separated values can be used to set multiple preferences:
--
-- >>> pPrint $ fromHeaders [("Prefer", "resolution=ignore-duplicates, count=exact")]
-- Preferences
-- { preferResolution = Just IgnoreDuplicates
-- , preferRepresentation = Nothing
-- , preferParameters = Nothing
-- , preferCount = Just ExactCount
-- , preferTransaction = Nothing
-- }
--
-- Multiple headers can also be used:
--
-- >>> pPrint $ fromHeaders [("Prefer", "resolution=ignore-duplicates"), ("Prefer", "count=exact")]
-- Preferences
-- { preferResolution = Just IgnoreDuplicates
-- , preferRepresentation = Nothing
-- , preferParameters = Nothing
-- , preferCount = Just ExactCount
-- , preferTransaction = Nothing
-- }
--
-- If a preference is set more than once, only the first is used:
--
-- >>> preferTransaction $ fromHeaders [("Prefer", "tx=commit, tx=rollback")]
-- Just Commit
--
-- This is also the case across multiple headers:
--
-- >>> :{
-- preferResolution . fromHeaders $
-- [ ("Prefer", "resolution=ignore-duplicates")
-- , ("Prefer", "resolution=merge-duplicates")
-- ]
-- :}
-- Just IgnoreDuplicates
--
-- Preferences not recognized by the application are ignored:
--
-- >>> preferResolution $ fromHeaders [("Prefer", "resolution=foo")]
-- Nothing
--
-- Preferences can be separated by arbitrary amounts of space, lower-case header is also recognized:
--
-- >>> pPrint $ fromHeaders [("prefer", "count=exact, tx=commit ,return=minimal")]
-- Preferences
-- { preferResolution = Nothing
-- , preferRepresentation = Just None
-- , preferParameters = Nothing
-- , preferCount = Just ExactCount
-- , preferTransaction = Just Commit
-- }
--
fromHeaders :: [HTTP.Header] -> Preferences
fromHeaders headers =
Preferences
{ preferResolution = parsePrefs [MergeDuplicates, IgnoreDuplicates]
, preferRepresentation = parsePrefs [Full, None, HeadersOnly]
, preferParameters = parsePrefs [SingleObject, MultipleObjects]
, preferCount = parsePrefs [ExactCount, PlannedCount, EstimatedCount]
, preferTransaction = parsePrefs [Commit, Rollback]
}
where
prefHeaders = filter ((==) HTTP.hPrefer . fst) headers
prefs = fmap BS.strip . concatMap (BS.split ',' . snd) $ prefHeaders
parsePrefs :: ToHeaderValue a => [a] -> Maybe a
parsePrefs vals =
head $ mapMaybe (flip Map.lookup $ prefMap vals) prefs
prefMap :: ToHeaderValue a => [a] -> Map.Map ByteString a
prefMap = Map.fromList . fmap (\pref -> (toHeaderValue pref, pref))
-- |
-- Convert a preference into the value that we look for in the 'Prefer' headers.
--
-- >>> toHeaderValue MergeDuplicates
-- "resolution=merge-duplicates"
--
class ToHeaderValue a where
toHeaderValue :: a -> ByteString
-- |
-- Header to indicate that a preference has been applied.
--
-- >>> toAppliedHeader MergeDuplicates
-- ("Preference-Applied","resolution=merge-duplicates")
--
class ToHeaderValue a => ToAppliedHeader a where
toAppliedHeader :: a -> HTTP.Header
toAppliedHeader x = (HTTP.hPreferenceApplied, toHeaderValue x)
-- | How to handle duplicate values.
data PreferResolution
= MergeDuplicates
| IgnoreDuplicates
instance ToHeaderValue PreferResolution where
toHeaderValue MergeDuplicates = "resolution=merge-duplicates"
toHeaderValue IgnoreDuplicates = "resolution=ignore-duplicates"
instance ToAppliedHeader PreferResolution
-- |
-- How to return the mutated data.
--
-- From https://tools.ietf.org/html/rfc7240#section-4.2
data PreferRepresentation
= Full -- ^ Return the body.
| HeadersOnly -- ^ Return the Location header(in case of POST). This needs a SELECT privilege on the pk.
| None -- ^ Return nothing from the mutated data.
deriving Eq
instance ToHeaderValue PreferRepresentation where
toHeaderValue Full = "return=representation"
toHeaderValue None = "return=minimal"
toHeaderValue HeadersOnly = "return=headers-only"
-- | How to pass parameters to stored procedures.
data PreferParameters
= SingleObject -- ^ Pass all parameters as a single json object to a stored procedure.
| MultipleObjects -- ^ Pass an array of json objects as params to a stored procedure.
deriving Eq
-- TODO: Deprecate params=multiple-objects in next major version
instance ToHeaderValue PreferParameters where
toHeaderValue SingleObject = "params=single-object"
toHeaderValue MultipleObjects = "params=multiple-objects"
-- | How to determine the count of (expected) results
data PreferCount
= ExactCount -- ^ Exact count (slower).
| PlannedCount -- ^ PostgreSQL query planner rows count guess. Done by using EXPLAIN {query}.
| EstimatedCount -- ^ Use the query planner rows if the count is superior to max-rows, otherwise get the exact count.
deriving Eq
instance ToHeaderValue PreferCount where
toHeaderValue ExactCount = "count=exact"
toHeaderValue PlannedCount = "count=planned"
toHeaderValue EstimatedCount = "count=estimated"
shouldCount :: Maybe PreferCount -> Bool
shouldCount prefCount =
prefCount == Just ExactCount || prefCount == Just EstimatedCount
-- | Whether to commit or roll back transactions.
data PreferTransaction
= Commit -- ^ Commit transaction - the default.
| Rollback -- ^ Rollback transaction after sending the response - does not persist changes, e.g. for running tests.
deriving Eq
instance ToHeaderValue PreferTransaction where
toHeaderValue Commit = "tx=commit"
toHeaderValue Rollback = "tx=rollback"
instance ToAppliedHeader PreferTransaction
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-- |
-- Module : PostgREST.ApiRequest.QueryParams
-- Description : Parser for PostgREST Query parameters
--
-- This module is in charge of parsing all the querystring values in an url, e.g.
-- the select, id, order in `/projects?select=id,name&id=eq.1&order=id,name.desc`.
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE TupleSections #-}
module PostgREST.ApiRequest.QueryParams
( parse
, QueryParams(..)
, pRequestRange
) where
import qualified Data.ByteString.Char8 as BS
import qualified Data.HashMap.Strict as HM
import qualified Data.List as L
import qualified Data.Set as S
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import qualified Network.HTTP.Base as HTTP
import qualified Network.HTTP.Types.URI as HTTP
import qualified Text.ParserCombinators.Parsec as P
import Control.Arrow ((***))
import Data.Either.Combinators (mapLeft)
import Data.List (init, last)
import Data.Ranged.Boundaries (Boundary (..))
import Data.Ranged.Ranges (Range (..))
import Data.Tree (Tree (..))
import Text.Parsec.Error (errorMessages,
showErrorMessages)
import Text.Parsec.Prim (parserFail)
import Text.ParserCombinators.Parsec (GenParser, ParseError, Parser,
anyChar, between, char, digit,
eof, errorPos, letter,
lookAhead, many1, noneOf,
notFollowedBy, oneOf,
optionMaybe, sepBy1, string,
try, (<?>))
import PostgREST.RangeQuery (NonnegRange, allRange,
rangeGeq, rangeLimit,
rangeOffset, restrictRange)
import PostgREST.SchemaCache.Identifiers (FieldName)
import PostgREST.ApiRequest.Types (EmbedParam (..), EmbedPath, Field,
Filter (..), FtsOperator (..),
JoinType (..), JsonOperand (..),
JsonOperation (..), JsonPath,
ListVal, LogicOperator (..),
LogicTree (..), OpExpr (..),
Operation (..),
OrderDirection (..),
OrderNulls (..), OrderTerm (..),
QPError (..), SelectItem,
SimpleOperator (..), SingleVal,
TrileanVal (..))
import Protolude hiding (try)
-- $setup
-- Setup for doctests
-- >>> import Text.Pretty.Simple (pPrint)
-- >>> deriving instance Show QPError
-- >>> deriving instance Show TrileanVal
-- >>> deriving instance Show FtsOperator
-- >>> deriving instance Show SimpleOperator
-- >>> deriving instance Show Operation
-- >>> deriving instance Show OpExpr
-- >>> deriving instance Show JsonOperand
-- >>> deriving instance Show JsonOperation
-- >>> deriving instance Show Filter
-- >>> deriving instance Show JoinType
data QueryParams =
QueryParams
{ qsCanonical :: ByteString
-- ^ Canonical representation of the query params, sorted alphabetically
, qsParams :: [(Text, Text)]
-- ^ Parameters for RPC calls
, qsRanges :: HM.HashMap Text (Range Integer)
-- ^ Ranges derived from &limit and &offset params
, qsOrder :: [(EmbedPath, [OrderTerm])]
-- ^ &order parameters for each level
, qsLogic :: [(EmbedPath, LogicTree)]
-- ^ &and and &or parameters used for complex boolean logic
, qsColumns :: Maybe (S.Set FieldName)
-- ^ &columns parameter and payload
, qsSelect :: [Tree SelectItem]
-- ^ &select parameter used to shape the response
, qsFilters :: [(EmbedPath, Filter)]
-- ^ Filters on the result from e.g. &id=e.10
, qsFiltersRoot :: [Filter]
-- ^ Subset of the filters that apply on the root table. These are used on UPDATE/DELETE.
, qsFiltersNotRoot :: [(EmbedPath, Filter)]
-- ^ Subset of the filters that do not apply on the root table
, qsFilterFields :: S.Set FieldName
-- ^ Set of fields that filters apply to
, qsOnConflict :: Maybe [FieldName]
-- ^ &on_conflict parameter used to upsert on specific unique keys
}
-- |
-- Parse query parameters from a query string like "id=eq.1&select=name".
--
-- The canonical representation of the query string has parameters sorted alphabetically:
--
-- >>> qsCanonical <$> parse "a=1&c=3&b=2&d"
-- Right "a=1&b=2&c=3&d="
--
-- 'select' is a reserved parameter that selects the fields to be returned:
--
-- >>> qsSelect <$> parse "select=name,location"
-- Right [Node {rootLabel = (("name",[]),Nothing,Nothing,Nothing,Nothing), subForest = []},Node {rootLabel = (("location",[]),Nothing,Nothing,Nothing,Nothing), subForest = []}]
--
-- Filters are parameters whose value contains an operator, separated by a '.' from its value:
--
-- >>> qsFilters <$> parse "a.b=eq.0"
-- Right [(["a"],Filter {field = ("b",[]), opExpr = OpExpr False (Op OpEqual "0")})]
--
-- If the operator specified in a filter does not exist, parsing the query string fails:
--
-- >>> qsFilters <$> parse "a.b=noop.0"
-- Left (QPError "\"failed to parse filter (noop.0)\" (line 1, column 6)" "unknown single value operator noop")
parse :: ByteString -> Either QPError QueryParams
parse qs =
QueryParams
canonical
params
ranges
<$> pRequestOrder `traverse` order
<*> pRequestLogicTree `traverse` logic
<*> pRequestColumns columns
<*> pRequestSelect select
<*> pRequestFilter `traverse` filters
<*> (fmap snd <$> (pRequestFilter `traverse` filtersRoot))
<*> pRequestFilter `traverse` filtersNotRoot
<*> pure (S.fromList (fst <$> filters))
<*> sequenceA (pRequestOnConflict <$> onConflict)
where
logic = filter (endingIn ["and", "or"] . fst) nonemptyParams
select = fromMaybe "*" $ lookupParam "select"
onConflict = lookupParam "on_conflict"
columns = lookupParam "columns"
order = filter (endingIn ["order"] . fst) nonemptyParams
limits = filter (endingIn ["limit"] . fst) nonemptyParams
-- Replace .offset ending with .limit to be able to match those params later in a map
offsets = first (replaceLast "limit") <$> filter (endingIn ["offset"] . fst) nonemptyParams
lookupParam :: Text -> Maybe Text
lookupParam needle = toS <$> join (L.lookup needle qParams)
nonemptyParams = mapMaybe (\(k, v) -> (k,) <$> v) qParams
qString = HTTP.parseQueryReplacePlus True qs
qParams = [(T.decodeUtf8 k, T.decodeUtf8 <$> v)|(k,v) <- qString]
canonical =
BS.pack $ HTTP.urlEncodeVars
. L.sortOn fst
. map (join (***) BS.unpack . second (fromMaybe mempty))
$ qString
endingIn:: [Text] -> Text -> Bool
endingIn xx key = lastWord `elem` xx
where lastWord = L.last $ T.split (== '.') key
(filters, params) = L.partition isParam filtersAndParams
isParam (k, v) = isEmbedPath k || hasOperator v || hasFtsOperator v
filtersAndParams = filter (isFilterOrParam . fst) nonemptyParams
isFilterOrParam k = not (endingIn reservedEmbeddable k) && notElem k reserved
reserved = ["select", "columns", "on_conflict"]
reservedEmbeddable = ["order", "limit", "offset", "and", "or"]
(filtersNotRoot, filtersRoot) = L.partition isNotRoot filters
isNotRoot = flip T.isInfixOf "." . fst
-- TODO: These checks are redundant to the parsers, should use parsers to differentiate params
hasOperator val =
case T.splitOn "." val of
"not" : _ : _ -> True
"is" : _ -> True
"in" : _ -> True
x : _ -> isJust (operator x) || isJust (ftsOperator x)
_ -> False
hasFtsOperator val =
case T.splitOn "(" val of
x : _ : _ -> isJust $ ftsOperator x
_ -> False
isEmbedPath = T.isInfixOf "."
replaceLast x s = T.intercalate "." $ L.init (T.split (=='.') s) <> [x]
ranges :: HM.HashMap Text (Range Integer)
ranges = HM.unionWith f limitParams offsetParams
where
f rl ro = Range (BoundaryBelow o) (BoundaryAbove $ o + l - 1)
where
l = fromMaybe 0 $ rangeLimit rl
o = rangeOffset ro
limitParams =
HM.fromList [(k, restrictRange (readMaybe v) allRange) | (k,v) <- limits]
offsetParams =
HM.fromList [(k, maybe allRange rangeGeq (readMaybe v)) | (k,v) <- offsets]
operator :: Text -> Maybe SimpleOperator
operator = \case
"eq" -> Just OpEqual
"gte" -> Just OpGreaterThanEqual
"gt" -> Just OpGreaterThan
"lte" -> Just OpLessThanEqual
"lt" -> Just OpLessThan
"neq" -> Just OpNotEqual
"like" -> Just OpLike
"ilike" -> Just OpILike
"cs" -> Just OpContains
"cd" -> Just OpContained
"ov" -> Just OpOverlap
"sl" -> Just OpStrictlyLeft
"sr" -> Just OpStrictlyRight
"nxr" -> Just OpNotExtendsRight
"nxl" -> Just OpNotExtendsLeft
"adj" -> Just OpAdjacent
"match" -> Just OpMatch
"imatch" -> Just OpIMatch
_ -> Nothing
ftsOperator :: Text -> Maybe FtsOperator
ftsOperator = \case
"fts" -> Just FilterFts
"plfts" -> Just FilterFtsPlain
"phfts" -> Just FilterFtsPhrase
"wfts" -> Just FilterFtsWebsearch
_ -> Nothing
-- PARSERS
pRequestSelect :: Text -> Either QPError [Tree SelectItem]
pRequestSelect selStr =
mapError $ P.parse pFieldForest ("failed to parse select parameter (" <> toS selStr <> ")") (toS selStr)
pRequestOnConflict :: Text -> Either QPError [FieldName]
pRequestOnConflict oncStr =
mapError $ P.parse pColumns ("failed to parse on_conflict parameter (" <> toS oncStr <> ")") (toS oncStr)
pRequestFilter :: (Text, Text) -> Either QPError (EmbedPath, Filter)
pRequestFilter (k, v) = mapError $ (,) <$> path <*> (Filter <$> fld <*> oper)
where
treePath = P.parse pTreePath ("failed to parse tree path (" ++ toS k ++ ")") $ toS k
oper = P.parse (pOpExpr pSingleVal) ("failed to parse filter (" ++ toS v ++ ")") $ toS v
path = fst <$> treePath
fld = snd <$> treePath
pRequestOrder :: (Text, Text) -> Either QPError (EmbedPath, [OrderTerm])
pRequestOrder (k, v) = mapError $ (,) <$> path <*> ord'
where
treePath = P.parse pTreePath ("failed to parse tree path (" ++ toS k ++ ")") $ toS k
path = fst <$> treePath
ord' = P.parse pOrder ("failed to parse order (" ++ toS v ++ ")") $ toS v
pRequestRange :: (Text, NonnegRange) -> Either QPError (EmbedPath, NonnegRange)
pRequestRange (k, v) = mapError $ (,) <$> path <*> pure v
where
treePath = P.parse pTreePath ("failed to parse tree path (" ++ toS k ++ ")") $ toS k
path = fst <$> treePath
pRequestLogicTree :: (Text, Text) -> Either QPError (EmbedPath, LogicTree)
pRequestLogicTree (k, v) = mapError $ (,) <$> embedPath <*> logicTree
where
path = P.parse pLogicPath ("failed to parse logic path (" ++ toS k ++ ")") $ toS k
embedPath = fst <$> path
logicTree = do
op <- snd <$> path
-- Concat op and v to make pLogicTree argument regular,
-- in the form of "?and=and(.. , ..)" instead of "?and=(.. , ..)"
P.parse pLogicTree ("failed to parse logic tree (" ++ toS v ++ ")") $ toS (op <> v)
pRequestColumns :: Maybe Text -> Either QPError (Maybe (S.Set FieldName))
pRequestColumns colStr =
case colStr of
Just str ->
mapError $ Just . S.fromList <$> P.parse pColumns ("failed to parse columns parameter (" <> toS str <> ")") (toS str)
_ -> Right Nothing
ws :: Parser Text
ws = toS <$> many (oneOf " \t")
lexeme :: Parser a -> Parser a
lexeme p = ws *> p <* ws
pTreePath :: Parser (EmbedPath, Field)
pTreePath = do
p <- pFieldName `sepBy1` pDelimiter
jp <- P.option [] pJsonPath
return (init p, (last p, jp))
pFieldForest :: Parser [Tree SelectItem]
pFieldForest = pFieldTree `sepBy1` lexeme (char ',')
where
pFieldTree :: Parser (Tree SelectItem)
pFieldTree = try (Node <$> pRelationSelect <*> between (char '(') (char ')') pFieldForest) <|>
Node <$> pFieldSelect <*> pure []
pStar :: Parser Text
pStar = string "*" $> "*"
pFieldName :: Parser Text
pFieldName =
pQuotedValue <|>
T.intercalate "-" . map toS <$> (many1 pIdentifierChar `sepBy1` dash) <?>
"field name (* or [a..z0..9_])"
where
isDash :: GenParser Char st ()
isDash = try ( char '-' >> notFollowedBy (char '>') )
dash :: Parser Char
dash = isDash $> '-'
-- |
-- Parse json operators in select, order and filters
--
-- >>> P.parse pJsonPath "" "->text"
-- Right [JArrow {jOp = JKey {jVal = "text"}}]
--
-- >>> P.parse pJsonPath "" "->1"
-- Right [JArrow {jOp = JIdx {jVal = "+1"}}]
--
-- >>> P.parse pJsonPath "" "->>text"
-- Right [J2Arrow {jOp = JKey {jVal = "text"}}]
--
-- >>> P.parse pJsonPath "" "->>1"
-- Right [J2Arrow {jOp = JIdx {jVal = "+1"}}]
--
-- >>> P.parse pJsonPath "" "->0,other"
-- Right [JArrow {jOp = JIdx {jVal = "+0"}}]
--
-- >>> P.parse pJsonPath "" "->0.desc"
-- Right [JArrow {jOp = JIdx {jVal = "+0"}}]
pJsonPath :: Parser JsonPath
pJsonPath = many pJsonOperation
where
pJsonOperation :: Parser JsonOperation
pJsonOperation = pJsonArrow <*> pJsonOperand
pJsonArrow =
try (string "->>" $> J2Arrow) <|>
try (string "->" $> JArrow)
pJsonOperand =
let pJKey = JKey . toS <$> pFieldName
pJIdx = JIdx . toS <$> ((:) <$> P.option '+' (char '-') <*> many1 digit) <* pEnd
pEnd = try (void $ lookAhead (string "->")) <|>
try (void $ lookAhead (string "::")) <|>
try (void $ lookAhead (string ".")) <|>
try (void $ lookAhead (string ",")) <|>
try eof in
try pJIdx <|> try pJKey
pField :: Parser Field
pField = lexeme $ (,) <$> pFieldName <*> P.option [] pJsonPath
aliasSeparator :: Parser ()
aliasSeparator = char ':' >> notFollowedBy (char ':')
pRelationSelect :: Parser SelectItem
pRelationSelect = lexeme $ try ( do
alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
fld <- pField
prm1 <- optionMaybe pEmbedParam
prm2 <- optionMaybe pEmbedParam
return (fld, Nothing, alias, embedParamHint prm1 <|> embedParamHint prm2, embedParamJoin prm1 <|> embedParamJoin prm2)
)
where
pEmbedParam :: Parser EmbedParam
pEmbedParam =
char '!' *> (
try (string "left" $> EPJoinType JTLeft) <|>
try (string "inner" $> EPJoinType JTInner) <|>
try (EPHint <$> pFieldName))
embedParamHint prm = case prm of
Just (EPHint hint) -> Just hint
_ -> Nothing
embedParamJoin prm = case prm of
Just (EPJoinType jt) -> Just jt
_ -> Nothing
pFieldSelect :: Parser SelectItem
pFieldSelect = lexeme $
try (
do
alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
fld <- pField
cast' <- optionMaybe (string "::" *> many pIdentifierChar)
return (fld, toS <$> cast', alias, Nothing, Nothing)
)
<|> do
s <- pStar
return ((s, []), Nothing, Nothing, Nothing, Nothing)
pOpExpr :: Parser SingleVal -> Parser OpExpr
pOpExpr pSVal = try ( string "not" *> pDelimiter *> (OpExpr True <$> pOperation)) <|> OpExpr False <$> pOperation
where
pOperation :: Parser Operation
pOperation = pIn <|> pIs <|> try pFts <|> pOp <?> "operator (eq, gt, ...)"
pIn = In <$> (try (string "in" *> pDelimiter) *> pListVal)
pIs = Is <$> (try (string "is" *> pDelimiter) *> pTriVal)
pOp = do
opStr <- try (P.manyTill anyChar (try pDelimiter))
op <- parseMaybe ("unknown single value operator " <> opStr) . operator $ toS opStr
Op op <$> pSVal
pTriVal = try (ciString "null" $> TriNull)
<|> try (ciString "unknown" $> TriUnknown)
<|> try (ciString "true" $> TriTrue)
<|> try (ciString "false" $> TriFalse)
<?> "null or trilean value (unknown, true, false)"
pFts = do
opStr <- try (P.many (noneOf ".("))
op <- parseMaybe ("unknown fts operator " <> opStr) . ftsOperator $ toS opStr
lang <- optionMaybe $ try (between (char '(') (char ')') $ many pIdentifierChar)
pDelimiter >> Fts op (toS <$> lang) <$> pSVal
parseMaybe :: [Char] -> Maybe a -> Parser a
parseMaybe err Nothing = parserFail err
parseMaybe _ (Just x) = pure x
-- case insensitive char and string
ciChar :: Char -> GenParser Char state Char
ciChar c = char c <|> char (toUpper c)
ciString :: [Char] -> GenParser Char state [Char]
ciString = traverse ciChar
pSingleVal :: Parser SingleVal
pSingleVal = toS <$> many anyChar
pListVal :: Parser ListVal
pListVal = lexeme (char '(') *> pListElement `sepBy1` char ',' <* lexeme (char ')')
pListElement :: Parser Text
pListElement = try (pQuotedValue <* notFollowedBy (noneOf ",)")) <|> (toS <$> many (noneOf ",)"))
pQuotedValue :: Parser Text
pQuotedValue = toS <$> (char '"' *> many pCharsOrSlashed <* char '"')
where
pCharsOrSlashed = noneOf "\\\"" <|> (char '\\' *> anyChar)
pDelimiter :: Parser Char
pDelimiter = char '.' <?> "delimiter (.)"
pOrder :: Parser [OrderTerm]
pOrder = lexeme pOrderTerm `sepBy1` char ','
pOrderTerm :: Parser OrderTerm
pOrderTerm = do
fld <- pField
dir <- optionMaybe $
try (pDelimiter *> string "asc" $> OrderAsc) <|>
try (pDelimiter *> string "desc" $> OrderDesc)
nls <- optionMaybe pNulls <* pEnd <|>
pEnd $> Nothing
return $ OrderTerm fld dir nls
where
pNulls = try (pDelimiter *> string "nullsfirst" $> OrderNullsFirst) <|>
try (pDelimiter *> string "nullslast" $> OrderNullsLast)
pEnd = try (void $ lookAhead (char ',')) <|>
try eof
pLogicTree :: Parser LogicTree
pLogicTree = Stmnt <$> try pLogicFilter
<|> Expr <$> pNot <*> pLogicOp <*> (lexeme (char '(') *> pLogicTree `sepBy1` lexeme (char ',') <* lexeme (char ')'))
where
pLogicFilter :: Parser Filter
pLogicFilter = Filter <$> pField <* pDelimiter <*> pOpExpr pLogicSingleVal
pNot :: Parser Bool
pNot = try (string "not" *> pDelimiter $> True)
<|> pure False
<?> "negation operator (not)"
pLogicOp :: Parser LogicOperator
pLogicOp = try (string "and" $> And)
<|> string "or" $> Or
<?> "logic operator (and, or)"
pLogicSingleVal :: Parser SingleVal
pLogicSingleVal = try (pQuotedValue <* notFollowedBy (noneOf ",)")) <|> try pPgArray <|> (toS <$> many (noneOf ",)"))
where
pPgArray :: Parser Text
pPgArray = do
a <- string "{"
b <- many (noneOf "{}")
c <- string "}"
pure (toS $ a ++ b ++ c)
pLogicPath :: Parser (EmbedPath, Text)
pLogicPath = do
path <- pFieldName `sepBy1` pDelimiter
let op = last path
notOp = "not." <> op
return (filter (/= "not") (init path), if "not" `elem` path then notOp else op)
pColumns :: Parser [FieldName]
pColumns = pFieldName `sepBy1` lexeme (char ',')
pIdentifierChar :: Parser Char
pIdentifierChar = letter <|> digit <|> oneOf "_ $"
mapError :: Either ParseError a -> Either QPError a
mapError = mapLeft translateError
where
translateError e =
QPError message details
where
message = show $ errorPos e
details = T.strip $ T.replace "\n" " " $ toS
$ showErrorMessages "or" "unknown parse error" "expecting" "unexpected" "end of input" (errorMessages e)
+214
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@@ -0,0 +1,214 @@
{-# LANGUAGE DuplicateRecordFields #-}
module PostgREST.ApiRequest.Types
( Alias
, Cast
, Depth
, EmbedParam(..)
, ApiRequestError(..)
, EmbedPath
, Field
, Filter(..)
, Hint
, JoinCondition(..)
, JoinType(..)
, JsonOperand(..)
, JsonOperation(..)
, JsonPath
, ListVal
, LogicOperator(..)
, LogicTree(..)
, NodeName
, OpExpr(..)
, Operation (..)
, OrderDirection(..)
, OrderNulls(..)
, OrderTerm(..)
, QPError(..)
, RangeError(..)
, SingleVal
, TrileanVal(..)
, SimpleOperator(..)
, FtsOperator(..)
, SelectItem
) where
import PostgREST.MediaType (MediaType (..))
import PostgREST.SchemaCache.Identifiers (FieldName,
QualifiedIdentifier)
import PostgREST.SchemaCache.Proc (ProcDescription (..))
import PostgREST.SchemaCache.Relationship (Relationship)
import Protolude
-- | The select value in `/tbl?select=alias:field::cast`
type SelectItem = (Field, Maybe Cast, Maybe Alias, Maybe Hint, Maybe JoinType)
data ApiRequestError
= AmbiguousRelBetween Text Text [Relationship]
| AmbiguousRpc [ProcDescription]
| BinaryFieldError MediaType
| MediaTypeError [ByteString]
| InvalidBody ByteString
| InvalidFilters
| InvalidRange RangeError
| InvalidRpcMethod ByteString
| LimitNoOrderError
| NotFound
| NoRelBetween Text Text Text
| NoRpc Text Text [Text] Bool MediaType Bool
| NotEmbedded Text
| ParseRequestError Text Text
| PutRangeNotAllowedError
| QueryParamError QPError
| UnacceptableSchema [Text]
| UnsupportedMethod ByteString
data QPError = QPError Text Text
data RangeError
= NegativeLimit
| LowerGTUpper
| OutOfBounds Text Text
type NodeName = Text
type Depth = Integer
data JoinCondition =
JoinCondition
(QualifiedIdentifier, FieldName)
(QualifiedIdentifier, FieldName)
deriving (Eq)
data OrderTerm = OrderTerm
{ otTerm :: Field
, otDirection :: Maybe OrderDirection
, otNullOrder :: Maybe OrderNulls
}
deriving (Eq)
data OrderDirection
= OrderAsc
| OrderDesc
deriving (Eq)
data OrderNulls
= OrderNullsFirst
| OrderNullsLast
deriving (Eq)
type Field = (FieldName, JsonPath)
type Cast = Text
type Alias = Text
type Hint = Text
data EmbedParam
-- | Disambiguates an embedding operation when there's multiple relationships
-- between two tables. Can be the name of a foreign key constraint, column
-- name or the junction in an m2m relationship.
= EPHint Hint
| EPJoinType JoinType
data JoinType
= JTInner
| JTLeft
deriving Eq
-- | Path of the embedded levels, e.g "clients.projects.name=eq.." gives Path
-- ["clients", "projects"]
type EmbedPath = [Text]
-- | Json path operations as specified in
-- https://www.postgresql.org/docs/current/static/functions-json.html
type JsonPath = [JsonOperation]
-- | Represents the single arrow `->` or double arrow `->>` operators
data JsonOperation
= JArrow { jOp :: JsonOperand }
| J2Arrow { jOp :: JsonOperand }
deriving (Eq)
-- | Represents the key(`->'key'`) or index(`->'1`::int`), the index is Text
-- because we reuse our escaping functons and let pg do the casting with
-- '1'::int
data JsonOperand
= JKey { jVal :: Text }
| JIdx { jVal :: Text }
deriving (Eq)
-- | Boolean logic expression tree e.g. "and(name.eq.N,or(id.eq.1,id.eq.2))" is:
--
-- And
-- / \
-- name.eq.N Or
-- / \
-- id.eq.1 id.eq.2
data LogicTree
= Expr Bool LogicOperator [LogicTree]
| Stmnt Filter
deriving (Eq)
data LogicOperator
= And
| Or
deriving Eq
data Filter = Filter
{ field :: Field
, opExpr :: OpExpr
}
deriving (Eq)
data OpExpr =
OpExpr Bool Operation
deriving (Eq)
data Operation
= Op SimpleOperator SingleVal
| In ListVal
| Is TrileanVal
| Fts FtsOperator (Maybe Language) SingleVal
deriving (Eq)
type Language = Text
-- | Represents a single value in a filter, e.g. id=eq.singleval
type SingleVal = Text
-- | Represents a list value in a filter, e.g. id=in.(val1,val2,val3)
type ListVal = [Text]
-- | Three-valued logic values
data TrileanVal
= TriTrue
| TriFalse
| TriNull
| TriUnknown
deriving Eq
data SimpleOperator
= OpEqual
| OpGreaterThanEqual
| OpGreaterThan
| OpLessThanEqual
| OpLessThan
| OpNotEqual
| OpLike
| OpILike
| OpContains
| OpContained
| OpOverlap
| OpStrictlyLeft
| OpStrictlyRight
| OpNotExtendsRight
| OpNotExtendsLeft
| OpAdjacent
| OpMatch
| OpIMatch
deriving Eq
-- | Operators for full text search operators
data FtsOperator
= FilterFts
| FilterFtsPlain
| FilterFtsPhrase
| FilterFtsWebsearch
deriving Eq