diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,5 @@ +# Revision history for cozo-hs + +## 0.1.0.0 -- 2023-11-03 + +* First version. Released on an unsuspecting world. diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,373 @@ +Mozilla Public License Version 2.0 +================================== + +1. Definitions +-------------- + +1.1. "Contributor" + means each individual or legal entity that creates, contributes to + the creation of, or owns Covered Software. + +1.2. "Contributor Version" + means the combination of the Contributions of others (if any) used + by a Contributor and that particular Contributor's Contribution. + +1.3. "Contribution" + means Covered Software of a particular Contributor. + +1.4. "Covered Software" + means Source Code Form to which the initial Contributor has attached + the notice in Exhibit A, the Executable Form of such Source Code + Form, and Modifications of such Source Code Form, in each case + including portions thereof. + +1.5. "Incompatible With Secondary Licenses" + means + + (a) that the initial Contributor has attached the notice described + in Exhibit B to the Covered Software; or + + (b) that the Covered Software was made available under the terms of + version 1.1 or earlier of the License, but not also under the + terms of a Secondary License. + +1.6. "Executable Form" + means any form of the work other than Source Code Form. + +1.7. "Larger Work" + means a work that combines Covered Software with other material, in + a separate file or files, that is not Covered Software. + +1.8. "License" + means this document. + +1.9. "Licensable" + means having the right to grant, to the maximum extent possible, + whether at the time of the initial grant or subsequently, any and + all of the rights conveyed by this License. + +1.10. "Modifications" + means any of the following: + + (a) any file in Source Code Form that results from an addition to, + deletion from, or modification of the contents of Covered + Software; or + + (b) any new file in Source Code Form that contains any Covered + Software. + +1.11. "Patent Claims" of a Contributor + means any patent claim(s), including without limitation, method, + process, and apparatus claims, in any patent Licensable by such + Contributor that would be infringed, but for the grant of the + License, by the making, using, selling, offering for sale, having + made, import, or transfer of either its Contributions or its + Contributor Version. + +1.12. "Secondary License" + means either the GNU General Public License, Version 2.0, the GNU + Lesser General Public License, Version 2.1, the GNU Affero General + Public License, Version 3.0, or any later versions of those + licenses. + +1.13. "Source Code Form" + means the form of the work preferred for making modifications. + +1.14. "You" (or "Your") + means an individual or a legal entity exercising rights under this + License. For legal entities, "You" includes any entity that + controls, is controlled by, or is under common control with You. For + purposes of this definition, "control" means (a) the power, direct + or indirect, to cause the direction or management of such entity, + whether by contract or otherwise, or (b) ownership of more than + fifty percent (50%) of the outstanding shares or beneficial + ownership of such entity. + +2. License Grants and Conditions +-------------------------------- + +2.1. Grants + +Each Contributor hereby grants You a world-wide, royalty-free, +non-exclusive license: + +(a) under intellectual property rights (other than patent or trademark) + Licensable by such Contributor to use, reproduce, make available, + modify, display, perform, distribute, and otherwise exploit its + Contributions, either on an unmodified basis, with Modifications, or + as part of a Larger Work; and + +(b) under Patent Claims of such Contributor to make, use, sell, offer + for sale, have made, import, and otherwise transfer either its + Contributions or its Contributor Version. + +2.2. Effective Date + +The licenses granted in Section 2.1 with respect to any Contribution +become effective for each Contribution on the date the Contributor first +distributes such Contribution. + +2.3. Limitations on Grant Scope + +The licenses granted in this Section 2 are the only rights granted under +this License. No additional rights or licenses will be implied from the +distribution or licensing of Covered Software under this License. +Notwithstanding Section 2.1(b) above, no patent license is granted by a +Contributor: + +(a) for any code that a Contributor has removed from Covered Software; + or + +(b) for infringements caused by: (i) Your and any other third party's + modifications of Covered Software, or (ii) the combination of its + Contributions with other software (except as part of its Contributor + Version); or + +(c) under Patent Claims infringed by Covered Software in the absence of + its Contributions. + +This License does not grant any rights in the trademarks, service marks, +or logos of any Contributor (except as may be necessary to comply with +the notice requirements in Section 3.4). + +2.4. Subsequent Licenses + +No Contributor makes additional grants as a result of Your choice to +distribute the Covered Software under a subsequent version of this +License (see Section 10.2) or under the terms of a Secondary License (if +permitted under the terms of Section 3.3). + +2.5. Representation + +Each Contributor represents that the Contributor believes its +Contributions are its original creation(s) or it has sufficient rights +to grant the rights to its Contributions conveyed by this License. + +2.6. Fair Use + +This License is not intended to limit any rights You have under +applicable copyright doctrines of fair use, fair dealing, or other +equivalents. + +2.7. Conditions + +Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted +in Section 2.1. + +3. Responsibilities +------------------- + +3.1. Distribution of Source Form + +All distribution of Covered Software in Source Code Form, including any +Modifications that You create or to which You contribute, must be under +the terms of this License. You must inform recipients that the Source +Code Form of the Covered Software is governed by the terms of this +License, and how they can obtain a copy of this License. You may not +attempt to alter or restrict the recipients' rights in the Source Code +Form. + +3.2. Distribution of Executable Form + +If You distribute Covered Software in Executable Form then: + +(a) such Covered Software must also be made available in Source Code + Form, as described in Section 3.1, and You must inform recipients of + the Executable Form how they can obtain a copy of such Source Code + Form by reasonable means in a timely manner, at a charge no more + than the cost of distribution to the recipient; and + +(b) You may distribute such Executable Form under the terms of this + License, or sublicense it under different terms, provided that the + license for the Executable Form does not attempt to limit or alter + the recipients' rights in the Source Code Form under this License. + +3.3. Distribution of a Larger Work + +You may create and distribute a Larger Work under terms of Your choice, +provided that You also comply with the requirements of this License for +the Covered Software. If the Larger Work is a combination of Covered +Software with a work governed by one or more Secondary Licenses, and the +Covered Software is not Incompatible With Secondary Licenses, this +License permits You to additionally distribute such Covered Software +under the terms of such Secondary License(s), so that the recipient of +the Larger Work may, at their option, further distribute the Covered +Software under the terms of either this License or such Secondary +License(s). + +3.4. Notices + +You may not remove or alter the substance of any license notices +(including copyright notices, patent notices, disclaimers of warranty, +or limitations of liability) contained within the Source Code Form of +the Covered Software, except that You may alter any license notices to +the extent required to remedy known factual inaccuracies. + +3.5. Application of Additional Terms + +You may choose to offer, and to charge a fee for, warranty, support, +indemnity or liability obligations to one or more recipients of Covered +Software. However, You may do so only on Your own behalf, and not on +behalf of any Contributor. You must make it absolutely clear that any +such warranty, support, indemnity, or liability obligation is offered by +You alone, and You hereby agree to indemnify every Contributor for any +liability incurred by such Contributor as a result of warranty, support, +indemnity or liability terms You offer. You may include additional +disclaimers of warranty and limitations of liability specific to any +jurisdiction. + +4. Inability to Comply Due to Statute or Regulation +--------------------------------------------------- + +If it is impossible for You to comply with any of the terms of this +License with respect to some or all of the Covered Software due to +statute, judicial order, or regulation then You must: (a) comply with +the terms of this License to the maximum extent possible; and (b) +describe the limitations and the code they affect. Such description must +be placed in a text file included with all distributions of the Covered +Software under this License. Except to the extent prohibited by statute +or regulation, such description must be sufficiently detailed for a +recipient of ordinary skill to be able to understand it. + +5. Termination +-------------- + +5.1. The rights granted under this License will terminate automatically +if You fail to comply with any of its terms. However, if You become +compliant, then the rights granted under this License from a particular +Contributor are reinstated (a) provisionally, unless and until such +Contributor explicitly and finally terminates Your grants, and (b) on an +ongoing basis, if such Contributor fails to notify You of the +non-compliance by some reasonable means prior to 60 days after You have +come back into compliance. Moreover, Your grants from a particular +Contributor are reinstated on an ongoing basis if such Contributor +notifies You of the non-compliance by some reasonable means, this is the +first time You have received notice of non-compliance with this License +from such Contributor, and You become compliant prior to 30 days after +Your receipt of the notice. + +5.2. If You initiate litigation against any entity by asserting a patent +infringement claim (excluding declaratory judgment actions, +counter-claims, and cross-claims) alleging that a Contributor Version +directly or indirectly infringes any patent, then the rights granted to +You by any and all Contributors for the Covered Software under Section +2.1 of this License shall terminate. + +5.3. In the event of termination under Sections 5.1 or 5.2 above, all +end user license agreements (excluding distributors and resellers) which +have been validly granted by You or Your distributors under this License +prior to termination shall survive termination. + +************************************************************************ +* * +* 6. Disclaimer of Warranty * +* ------------------------- * +* * +* Covered Software is provided under this License on an "as is" * +* basis, without warranty of any kind, either expressed, implied, or * +* statutory, including, without limitation, warranties that the * +* Covered Software is free of defects, merchantable, fit for a * +* particular purpose or non-infringing. The entire risk as to the * +* quality and performance of the Covered Software is with You. * +* Should any Covered Software prove defective in any respect, You * +* (not any Contributor) assume the cost of any necessary servicing, * +* repair, or correction. This disclaimer of warranty constitutes an * +* essential part of this License. No use of any Covered Software is * +* authorized under this License except under this disclaimer. * +* * +************************************************************************ + +************************************************************************ +* * +* 7. Limitation of Liability * +* -------------------------- * +* * +* Under no circumstances and under no legal theory, whether tort * +* (including negligence), contract, or otherwise, shall any * +* Contributor, or anyone who distributes Covered Software as * +* permitted above, be liable to You for any direct, indirect, * +* special, incidental, or consequential damages of any character * +* including, without limitation, damages for lost profits, loss of * +* goodwill, work stoppage, computer failure or malfunction, or any * +* and all other commercial damages or losses, even if such party * +* shall have been informed of the possibility of such damages. This * +* limitation of liability shall not apply to liability for death or * +* personal injury resulting from such party's negligence to the * +* extent applicable law prohibits such limitation. Some * +* jurisdictions do not allow the exclusion or limitation of * +* incidental or consequential damages, so this exclusion and * +* limitation may not apply to You. * +* * +************************************************************************ + +8. Litigation +------------- + +Any litigation relating to this License may be brought only in the +courts of a jurisdiction where the defendant maintains its principal +place of business and such litigation shall be governed by laws of that +jurisdiction, without reference to its conflict-of-law provisions. +Nothing in this Section shall prevent a party's ability to bring +cross-claims or counter-claims. + +9. Miscellaneous +---------------- + +This License represents the complete agreement concerning the subject +matter hereof. If any provision of this License is held to be +unenforceable, such provision shall be reformed only to the extent +necessary to make it enforceable. Any law or regulation which provides +that the language of a contract shall be construed against the drafter +shall not be used to construe this License against a Contributor. + +10. Versions of the License +--------------------------- + +10.1. New Versions + +Mozilla Foundation is the license steward. Except as provided in Section +10.3, no one other than the license steward has the right to modify or +publish new versions of this License. Each version will be given a +distinguishing version number. + +10.2. Effect of New Versions + +You may distribute the Covered Software under the terms of the version +of the License under which You originally received the Covered Software, +or under the terms of any subsequent version published by the license +steward. + +10.3. Modified Versions + +If you create software not governed by this License, and you want to +create a new license for such software, you may create and use a +modified version of this License if you rename the license and remove +any references to the name of the license steward (except to note that +such modified license differs from this License). + +10.4. Distributing Source Code Form that is Incompatible With Secondary +Licenses + +If You choose to distribute Source Code Form that is Incompatible With +Secondary Licenses under the terms of this version of the License, the +notice described in Exhibit B of this License must be attached. + +Exhibit A - Source Code Form License Notice +------------------------------------------- + + This Source Code Form is subject to the terms of the Mozilla Public + License, v. 2.0. If a copy of the MPL was not distributed with this + file, You can obtain one at http://mozilla.org/MPL/2.0/. + +If it is not possible or desirable to put the notice in a particular +file, then You may include the notice in a location (such as a LICENSE +file in a relevant directory) where a recipient would be likely to look +for such a notice. + +You may add additional accurate notices of copyright ownership. + +Exhibit B - "Incompatible With Secondary Licenses" Notice +--------------------------------------------------------- + + This Source Code Form is "Incompatible With Secondary Licenses", as + defined by the Mozilla Public License, v. 2.0. diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,61 @@ +# cozo-hs + +### A library with bindings and simple types to the C API of the embeddable Cozo database. + +## Installation + +This library relies on pkg-config for libcozo_c being available on your system. You will need to have `cozo_c.h` and `libcozo_c.so` installed somewhere your linker can find it and it must be registered with pkg-config. + +To do so, you can download both the header files as well as the library from the [Cozo project repository](https://github.com/cozodb/cozo) or you could clone that repository and build it from source. + +If there is no official way to install this library on your OS/Distro (Debian for example) then you can put the library and headers in common paths (/usr/local/lib, /usr/local/include respectively) then manually create a pkg-config file for them. Just make sure that the version you specify matches what you have installed! + +Here is an example libcozo_c.pc: +``` +Name: cozo_c +Description: C Interface with the Cozo embeddable database. +Version: 0.7.5 +Cflags: -I/usr/local/include +Libs: -L/usr/local/lib -lcozo_c +``` + +After that, a simple `cabal build` can make sure that the C compiler is linking correctly. + +After building, you may want to ensure that the runtime is linked correctly as well. Run `cabal repl` to try out some of the code or `cabal test` to run the test-suite. + +Following all of this, you can include this library as a dependency in other Cabal projects the normal way. + +## Notes on Usage + +This library makes heavy use of aeson given that the C API is defined almost entirely in terms of JSON. Therefore, some primitive data types which match the structure of returned JSON are provided as part of this library. + +If you desire to use your own serialization scheme rather than the types provided, the underlying bindings are exposed in the form of functions with a `'` suffix. All of these functions deal with strict `ByteStrings` that are marshalled from the strings produced by C. + +All errors are handled in a pure Either. + +A very simple program which opens an in-memory connection and runs a query is as follows: +```Haskell +{-#LANGUAGE OverloadedStrings#-} +import Database.Cozo +import Control.Exception (bracket, throwIO) + +main :: IO () +main = + bracket + (open "mem" "" "{}" >>= either throwIO pure) + (fmap (const ()) . close) + $ \c -> do + er <- runQuery c "?[] <- [[1,2,3]]" KM.empty + case er of + Left e -> throwIO e + Right (CozoResult badOkay) -> + case badOkay of + Left bad -> print . cozoBadMessage $ bad + Right okay -> print . namedRowsRows . cozoOkayNamedRows $ okay +``` + +This program will output: + +``` +[[Number 1.0,Number 2.0,Number 3.0]] +``` diff --git a/cozo-hs.cabal b/cozo-hs.cabal new file mode 100644 --- /dev/null +++ b/cozo-hs.cabal @@ -0,0 +1,55 @@ +cabal-version: 3.0 +name: cozo-hs +version: 0.1.0.0 +synopsis: Haskell bindings to the CozoDB C API +description: Simple, relatively low-level bindings to the C API + provided by cozo. Additionally, there are some convenience types for + serializing function arguments and deserializing query results. +license: MPL-2.0 +license-file: LICENSE +author: Henry Johnson +maintainer: hencutJohnson@gmail.com +-- copyright: +category: Database +build-type: Simple +extra-doc-files: CHANGELOG.md + README.md + +common warnings + ghc-options: -Wall + +library + import: warnings + exposed-modules: + Database.Cozo + other-modules: + Database.Cozo.Internal + Database.Cozo.Internal.Bindings + other-extensions: + CApiFFI + ForeignFunctionInterface + OverloadedStrings + StrictData + build-depends: + base ^>=4.18.0.0, + aeson >= 2.2.1 && < 2.3, + bytestring >= 0.11.4 && < 0.12, + text >= 2.0.2 && < 2.1, + hs-source-dirs: src + default-language: GHC2021 + pkgconfig-depends: libcozo_c == 0.7.5 + +test-suite cozo-hs-test + import: warnings + build-depends: + base ^>= 4.18.0.0, + cozo-hs, + aeson >= 2.2.1 && < 2.3, + bytestring >= 0.11.4 && < 0.12, + text >= 2.0.2 && < 2.1, + tasty == 1.5, + tasty-hunit == 0.10.1 + type: exitcode-stdio-1.0 + main-is: Main.hs + hs-source-dirs: test + default-language: GHC2021 diff --git a/src/Database/Cozo.hs b/src/Database/Cozo.hs new file mode 100644 --- /dev/null +++ b/src/Database/Cozo.hs @@ -0,0 +1,495 @@ +{-# HLINT ignore "Use const" #-} +{-# HLINT ignore "Eta reduce" #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE StrictData #-} +{-# OPTIONS_GHC -Wno-typed-holes #-} +{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-} + +{- | +Module : Database.Cozo +Description : Wrappers and types for the Cozo C API +License : MPL-2.0 +Maintainer : hencutJohnson@gmail.com + +Included are some wrapping functions for Cozo's C API and data types to deserialize them. +-} +module Database.Cozo ( + -- * Data + CozoResult (..), + CozoOkay (..), + NamedRows (..), + CozoBad (..), + CozoRelationExportPayload (..), + CozoException (..), + + -- * Functions + open, + close, + runQuery, + backup, + restore, + importRelations, + exportRelations, + importFromBackup, + + -- ** Lower Level Wrappers + open', + close', + runQuery', + backup', + restore', + importRelations', + exportRelations', + importFromBackup', + + -- * Re-exports + Connection, + CozoNullResultPtrException, + Database.Cozo.Internal.InternalCozoError, + Key, + KeyMap, + KM.empty, + KM.singleton, + KM.insert, + KM.fromList, + Value (..), +) where + +import Control.Exception (Exception) +import Data.Aeson ( + FromJSON (parseJSON), + Options (fieldLabelModifier), + ToJSON (..), + Value (..), + defaultOptions, + eitherDecodeStrict, + fromEncoding, + genericParseJSON, + genericToEncoding, + genericToJSON, + withObject, + (.:), + ) +import Data.Aeson.KeyMap (Key, KeyMap) +import Data.Aeson.KeyMap qualified as KM +import Data.Aeson.Types (Encoding, Parser) +import Data.Bifunctor (Bifunctor (bimap, first)) +import Data.ByteString (ByteString, toStrict) +import Data.ByteString.Builder (toLazyByteString) +import Data.Char (toLower) +import Data.Text (Text) +import Data.Text.Encoding (encodeUtf8) +import Database.Cozo.Internal ( + Connection, + CozoNullResultPtrException, + InternalCozoError, + backup', + close', + exportRelations', + importFromBackup', + importRelations', + open', + restore', + runQuery', + ) +import GHC.Generics (Generic) + +{- | +Relation information with headers, their values, and another `NamedRows` if +it exists. +-} +data NamedRows = NamedRows + { namedRowsHeaders :: [Text] + , namedRowsRows :: [[Value]] + , namedRowsNext :: Maybe NamedRows + } + deriving (Show, Eq, Generic) + +instance FromJSON NamedRows where + parseJSON :: Value -> Parser NamedRows + parseJSON = + genericParseJSON + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 9 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + +instance ToJSON NamedRows where + toJSON :: NamedRows -> Value + toJSON = + genericToJSON + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 9 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + toEncoding :: NamedRows -> Encoding + toEncoding = + genericToEncoding + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 9 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + +data ConstJSON = ConstJSON deriving (Show, Eq, Generic) + +instance FromJSON ConstJSON where + parseJSON :: Value -> Parser ConstJSON + parseJSON _ = pure ConstJSON + +{- | +A failure that cannot be recovered from easily. +-} +data CozoException + = -- | An internal error may occur when a connection is first being established + -- but not after that. + CozoExceptionInternal InternalCozoError + | -- | If any operation in the underlying C API returns a null pointer instead + -- of a pointer to a valid string, this error will be returned. + CozoErrorNullPtr CozoNullResultPtrException + | -- | The result of any operation fails to be deserialized appropriately. + -- This is a problem with the wrapper for the API and should be + -- submitted as an issue if it ever arises. + CozoJSONParseException String + | -- | A non-query operation such as a backup or import failed. + -- These usually occur because the user is trying to import or export a + -- relation that does not exist in the target database. + CozoOperationFailed Text + deriving (Show, Eq, Generic) + +instance Exception CozoException + +newtype CozoMessage = CozoMessage {runCozoMessage :: Text} + deriving (Show, Eq, Generic) + +instance FromJSON CozoMessage where + parseJSON :: Value -> Parser CozoMessage + parseJSON = + genericParseJSON + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 7 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + +cozoMessageToException :: CozoMessage -> CozoException +cozoMessageToException (CozoMessage m) = CozoOperationFailed m + +{- | +A map of names and the relations they contain. +This type is intended to be used as input to an import function +or otherwise stored as JSON. +-} +newtype CozoRelationExportPayload = CozoRelationExportPayload + { cozoRelationExportPayloadData :: KeyMap NamedRows + } + deriving (Show, Eq, Generic) + +instance FromJSON CozoRelationExportPayload where + parseJSON :: Value -> Parser CozoRelationExportPayload + parseJSON = + genericParseJSON + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 25 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + +{- | +An intermediate type for decoding structures that return an object with a 'message' field +when the 'ok' field is false. +-} +newtype IntermediateCozoMessageOnNotOK a = IntermediateCozoMessageOnNotOK + { runIntermediateCozoMessageOnNotOK :: Either CozoMessage a + } + deriving (Show, Eq, Generic) + +instance (FromJSON a) => FromJSON (IntermediateCozoMessageOnNotOK a) where + parseJSON :: Value -> Parser (IntermediateCozoMessageOnNotOK a) + parseJSON = + eitherOkay + "IntermediateCozoRelationExport" + (fmap (IntermediateCozoMessageOnNotOK . Left) . parseJSON) + (fmap (IntermediateCozoMessageOnNotOK . Right) . parseJSON) + +data IntermediateCozoImportFromRelationInput = IntermediateCozoImportFromRelationInput + { intermediateCozoImportFromRelationInputPath :: Text + , intermediateCozoImportFromRelationInputRelations :: [Text] + } + deriving (Show, Eq, Generic) + +instance ToJSON IntermediateCozoImportFromRelationInput where + toJSON :: IntermediateCozoImportFromRelationInput -> Value + toJSON = + genericToJSON + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 39 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + toEncoding :: IntermediateCozoImportFromRelationInput -> Encoding + toEncoding = + genericToEncoding + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 39 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + +{- | +An intermediate type for packing a list of named relations into an object with the form +\"{'relations': [...]}\" +-} +newtype IntermediateCozoRelationInput = IntermediateCozoRelationInput + { intermediateCozoRelationInputRelations :: [Text] + } + deriving (Show, Eq, Generic) + +instance ToJSON IntermediateCozoRelationInput where + toJSON :: IntermediateCozoRelationInput -> Value + toJSON = + genericToJSON + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 29 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + toEncoding :: + IntermediateCozoRelationInput -> + Encoding + toEncoding = + genericToEncoding + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 29 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + +{- | +An okay result from a query. + +Contains result headers, and rows among other things. +-} +data CozoOkay = CozoOkay + { cozoOkayNamedRows :: NamedRows + , cozoOkayTook :: Double + } + deriving (Show, Eq, Generic) + +instance FromJSON CozoOkay where + parseJSON :: Value -> Parser CozoOkay + parseJSON = + withObject "CozoOkay" $ \o -> + CozoOkay + <$> parseJSON (Object o) + <*> o + .: "took" + +{- | +A bad result from a query. + +Contains information on what went wrong. +-} +data CozoBad = CozoBad + { cozoBadDisplay :: Maybe Text + , cozoBadMessage :: Text + , cozoBadSeverity :: Maybe Text + } + deriving (Show, Eq, Generic) + +instance FromJSON CozoBad where + parseJSON :: Value -> Parser CozoBad + parseJSON = + genericParseJSON + ( defaultOptions + { fieldLabelModifier = \s -> + case drop 7 s of + [] -> [] + x : xs -> toLower x : xs + } + ) + +newtype CozoResult = CozoResult {runCozoResult :: Either CozoBad CozoOkay} + deriving (Show, Eq, Generic) + +instance FromJSON CozoResult where + parseJSON :: Value -> Parser CozoResult + parseJSON = + eitherOkay + "CozoResult" + (fmap (CozoResult . Left) . parseJSON) + (fmap (CozoResult . Right) . parseJSON) + +{- | +Open a connection to a cozo database + +- engine: \"mem\", \"sqlite\" or \"rocksdb\" +- path: utf8 encoded filepath +- options: engine-specific options. \"{}\" is an acceptable empty value. +-} +open :: Text -> Text -> Text -> IO (Either CozoException Connection) +open engine path options = + first CozoExceptionInternal + <$> open' + (encodeUtf8 engine) + (encodeUtf8 path) + (encodeUtf8 options) + +{- | +True if the database was closed and False if it was already closed or if it +does not exist. +-} +close :: Connection -> IO Bool +close = close' + +{- | +Run a utf8 encoded query with a map of parameters. + +Parameters are declared with +text names and can be any valid JSON type. They are referenced in a query by a \"$\" +preceding their name. +-} +runQuery :: + Connection -> + Text -> + KeyMap Value -> + IO (Either CozoException CozoResult) +runQuery c query params = do + r <- + runQuery' + c + (encodeUtf8 query) + ( toStrict + . toLazyByteString + . fromEncoding + . toEncoding + $ params + ) + pure $ first CozoErrorNullPtr r >>= cozoDecode + +{- | +Backup a database. + +Accepts the path of the output file. +-} +backup :: Connection -> Text -> IO (Either CozoException ()) +backup c path = + decodeCozoCharPtrFn + <$> backup' c (encodeUtf8 path) + +{- | +Restore a database from a backup. +-} +restore :: Connection -> Text -> IO (Either CozoException ()) +restore c path = + decodeCozoCharPtrFn + <$> restore' c (encodeUtf8 path) + +{- | +Import data in relations. + +Triggers are not run for relations, if you wish to activate triggers, use a query + with parameters. +-} +importRelations :: + Connection -> + CozoRelationExportPayload -> + IO (Either CozoException ()) +importRelations c (CozoRelationExportPayload km) = + decodeCozoCharPtrFn + <$> importRelations' c (strictToEncoding km) + +{- | +Export the relations specified by the given names. +-} +exportRelations :: + Connection -> + [Text] -> + IO (Either CozoException CozoRelationExportPayload) +exportRelations c bs = do + r <- + exportRelations' + c + ( strictToEncoding + . IntermediateCozoRelationInput + $ bs + ) + pure + $ first CozoErrorNullPtr r + >>= first CozoJSONParseException + . eitherDecodeStrict @(IntermediateCozoMessageOnNotOK CozoRelationExportPayload) + >>= first cozoMessageToException + . runIntermediateCozoMessageOnNotOK + +{- | +Import the relations corresponding to the given names +from the specified path. +-} +importFromBackup :: Connection -> Text -> [Text] -> IO (Either CozoException ()) +importFromBackup c path relations = + decodeCozoCharPtrFn + <$> importFromBackup' + c + (strictToEncoding $ IntermediateCozoImportFromRelationInput path relations) + +decodeCozoCharPtrFn :: + Either CozoNullResultPtrException ByteString -> + Either CozoException () +decodeCozoCharPtrFn e = + first CozoErrorNullPtr e + >>= cozoDecode @(IntermediateCozoMessageOnNotOK ConstJSON) + >>= bimap cozoMessageToException (const ()) + . runIntermediateCozoMessageOnNotOK + +cozoDecode :: (FromJSON a) => ByteString -> Either CozoException a +cozoDecode = first CozoJSONParseException . eitherDecodeStrict + +{- | +Helper for defining JSON disjunctions that +switch on the value of an \"ok\" boolean field. +-} +eitherOkay :: + String -> + (Value -> Parser a) -> + (Value -> Parser a) -> + Value -> + Parser a +eitherOkay s l r = + withObject + s + ( \o -> + case KM.lookup "ok" o of + Nothing -> fail "Result did not contain \"ok\" field" + Just ok -> + case ok of + Bool b -> + if b then r (Object o) else l (Object o) + _ -> fail "\"ok\" field did not contain a Boolean." + ) + +strictToEncoding :: (ToJSON a) => a -> ByteString +strictToEncoding = + toStrict + . toLazyByteString + . fromEncoding + . toEncoding diff --git a/src/Database/Cozo/Internal.hs b/src/Database/Cozo/Internal.hs new file mode 100644 --- /dev/null +++ b/src/Database/Cozo/Internal.hs @@ -0,0 +1,198 @@ +{-# LANGUAGE StrictData #-} +{-# OPTIONS_GHC -Wno-typed-holes #-} +{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-} +{-# OPTIONS_HADDOCK hide #-} + +{-# HLINT ignore "Use newtype instead of data" #-} + +module Database.Cozo.Internal ( + open', + close', + runQuery', + importRelations', + exportRelations', + backup', + restore', + importFromBackup', + Connection, + InternalCozoError (..), + CozoNullResultPtrException (..), +) where + +import Control.Exception (Exception) +import Control.Monad ((<=<)) +import Data.ByteString (ByteString) +import Data.ByteString qualified as B +import Data.Coerce (coerce) +import Database.Cozo.Internal.Bindings ( + cozoBackup, + cozoCloseDB, + cozoExportRelations, + cozoFreeStr, + cozoImportFromBackup, + cozoImportRelations, + cozoOpenDB, + cozoRestore, + cozoRunQuery, + ) +import Foreign ( + Ptr, + Storable (peek), + fromBool, + maybePeek, + new, + toBool, + ) +import Foreign.C.Types (CChar, CInt) +import GHC.Generics (Generic) + +newtype Connection = Connection (Ptr CInt) + +{- | +Wrapper around primitive failure states. +-} +newtype InternalCozoError + = InternalCozoError ByteString + deriving (Show, Eq, Generic) + +instance Exception InternalCozoError + +data CozoNullResultPtrException = CozoNullResultPtrException deriving (Show, Eq, Generic) + +instance Exception CozoNullResultPtrException + +{- | +Open a connection to a cozo database + +- engine: \"mem\", \"sqlite\" or \"rocksdb\" +- path: utf8 encoded filepath +- options: engine-specific options. \"{}\" is an acceptable empty value. +-} +open' :: + -- | engine: \"mem\", \"sqlite\" or \"rocksdb\" + ByteString -> + -- | path: utf8 encoded filepath + ByteString -> + -- | options: engine-specific options. \"{}\" is an acceptable emtpy value. + ByteString -> + IO (Either InternalCozoError Connection) +open' engineBs pathBs optionBs = + B.useAsCString engineBs $ \engine -> + B.useAsCString pathBs $ \path -> + B.useAsCString optionBs $ \options -> do + intPtr <- new @CInt 0 + openMessagePtr <- cozoOpenDB engine path options intPtr + !mOpenMessage <- maybePeek B.packCString openMessagePtr + maybe + (pure . Right . Connection $ intPtr) + (\errStr -> (Left . InternalCozoError $ errStr) <$ cozoFreeStr openMessagePtr) + mOpenMessage + +{- | +True if the database was closed and False if it was already closed or if it +does not exist. +-} +close' :: Connection -> IO Bool +close' = fmap toBool . cozoCloseDB <=< peek . coerce + +{- | +Run a query. + +The `CozoError` that might arise from this function is a `CozoNullResultPtr`. +If there are any errors internal to cozo, those will be returned as part of the +JSON string returned in the Right value. Simple returning a Right value does not +mean the query was successful. + +- script: utf8 encoded script to execute +- params_raw: a utf8 encoded, JSON formatted map of parameters for use in the script. +-} +runQuery' :: + Connection -> + ByteString -> + ByteString -> + IO (Either CozoNullResultPtrException ByteString) +runQuery' c q p = + B.useAsCString q $ \q' -> + B.useAsCString p $ \p' -> + cozoCharPtrFn (\i -> cozoRunQuery i q' p' (fromBool False)) c + +{- | +Import data in relations. + +Triggers are not run for relations, if you wish to activate triggers, use a query + with parameters. + +The given bytestring is a utf8, JSON formatted payload of relations. +In the same form as that given by `exportRelations'` +-} +importRelations' :: + Connection -> + ByteString -> + IO (Either CozoNullResultPtrException ByteString) +importRelations' c payloadBs = + B.useAsCString payloadBs $ \payload -> + cozoCharPtrFn (`cozoImportRelations` payload) c + +{- | +Export relations into JSON + +The given bytestring must be a utf8 encoded JSON payload. See the manual for expected +fields. +-} +exportRelations' :: + Connection -> + ByteString -> + IO (Either CozoNullResultPtrException ByteString) +exportRelations' c payloadBs = + B.useAsCString payloadBs $ \payload -> + cozoCharPtrFn (`cozoExportRelations` payload) c + +{- | +Backup a database. + +Accepts the path of the output file. +-} +backup' :: Connection -> ByteString -> IO (Either CozoNullResultPtrException ByteString) +backup' c pathBs = + B.useAsCString pathBs $ \path -> + cozoCharPtrFn (`cozoBackup` path) c + +{- | +Restore a database from a backup. +-} +restore' :: Connection -> ByteString -> IO (Either CozoNullResultPtrException ByteString) +restore' c pathBs = + B.useAsCString pathBs $ \path -> + cozoCharPtrFn (`cozoRestore` path) c + +{- | +Import relations from a backup. + +Note that triggers are not run for the relations. +To run triggers, use a query with parameters. + +- payload: @"{'path': ..., 'relations': [...]}"@ +-} +importFromBackup' :: + Connection -> + ByteString -> + IO (Either CozoNullResultPtrException ByteString) +importFromBackup' c payloadBs = + B.useAsCString payloadBs $ \payload -> + cozoCharPtrFn (`cozoImportFromBackup` payload) c + +{- | +Helper function for using cozo bindings that do an action and return a +string that needs to be freed. +-} +cozoCharPtrFn :: + (CInt -> IO (Ptr CChar)) -> + Connection -> + IO (Either CozoNullResultPtrException ByteString) +cozoCharPtrFn a (Connection intPtr) = do + dbId <- peek intPtr + rPtr <- a dbId + !mR <- maybePeek B.packCString rPtr + case mR of + Nothing -> pure . Left $ CozoNullResultPtrException + Just r -> Right r <$ cozoFreeStr rPtr diff --git a/src/Database/Cozo/Internal/Bindings.hs b/src/Database/Cozo/Internal/Bindings.hs new file mode 100644 --- /dev/null +++ b/src/Database/Cozo/Internal/Bindings.hs @@ -0,0 +1,45 @@ +{-# LANGUAGE CApiFFI #-} +{-# LANGUAGE ForeignFunctionInterface #-} +{-# OPTIONS_HADDOCK hide #-} + +module Database.Cozo.Internal.Bindings ( + cozoOpenDB, + cozoCloseDB, + cozoRunQuery, + cozoImportRelations, + cozoExportRelations, + cozoBackup, + cozoRestore, + cozoImportFromBackup, + cozoFreeStr, +) where + +import Foreign.C.Types (CBool (..), CChar, CInt (..)) +import Foreign.Ptr (Ptr) + +foreign import capi "cozo_c.h cozo_open_db" + cozoOpenDB :: Ptr CChar -> Ptr CChar -> Ptr CChar -> Ptr CInt -> IO (Ptr CChar) + +foreign import capi "cozo_c.h cozo_close_db" + cozoCloseDB :: CInt -> IO CBool + +foreign import capi "cozo_c.h cozo_run_query" + cozoRunQuery :: CInt -> Ptr CChar -> Ptr CChar -> CBool -> IO (Ptr CChar) + +foreign import capi "cozo_c.h cozo_import_relations" + cozoImportRelations :: CInt -> Ptr CChar -> IO (Ptr CChar) + +foreign import capi "cozo_c.h cozo_export_relations" + cozoExportRelations :: CInt -> Ptr CChar -> IO (Ptr CChar) + +foreign import capi "cozo_c.h cozo_backup" + cozoBackup :: CInt -> Ptr CChar -> IO (Ptr CChar) + +foreign import capi "cozo_c.h cozo_restore" + cozoRestore :: CInt -> Ptr CChar -> IO (Ptr CChar) + +foreign import capi "cozo_c.h cozo_import_from_backup" + cozoImportFromBackup :: CInt -> Ptr CChar -> IO (Ptr CChar) + +foreign import capi "cozo_c.h cozo_free_str" + cozoFreeStr :: Ptr CChar -> IO () diff --git a/test/Main.hs b/test/Main.hs new file mode 100644 --- /dev/null +++ b/test/Main.hs @@ -0,0 +1,96 @@ +{-# LANGUAGE OverloadedStrings #-} +{-# OPTIONS_GHC -Wno-typed-holes #-} + +import Control.Exception (bracket, throwIO) +import Data.Aeson (toJSON) +import Data.Either (isLeft) +import Database.Cozo +import Test.Tasty +import Test.Tasty.HUnit + +main :: IO () +main = + defaultMain + . testGroup "cozo-hs Tests" + $ [ connectionTests + , withResource + (open "mem" "" "{}" >>= either throwIO pure) + ((() <$) . close) + runQueryTests + , exportAndImportTests + ] + +connectionTests :: (HasCallStack) => TestTree +connectionTests = + testGroup + "Connection Tests" + [ testCase "Establish Connection" + $ open "mem" "" "{}" + >>= either throwIO pure + >>= close + >>= assertBool "Database was already closed or did not exist." + ] + +exportAndImportTests :: (HasCallStack) => TestTree +exportAndImportTests = + testGroup + "Export and Import Tests" + [ testCase "Can export and import" $ do + e <- + testWithConnection + $ \c -> do + _ <- + runQuery + c + "?[foo] <- [['foo']]; \ + \:create Foo{foo:String}" + empty + >>= either throwIO pure + exportRelations c ["Foo"] >>= either throwIO pure + (CozoResult (Right o)) <- testWithConnection $ \c -> do + _ <- runQuery c ":create Foo{foo:String}" empty >>= either throwIO pure + _ <- importRelations c e + runQuery c "?[foo] := *Foo{foo}" empty >>= either throwIO pure + + assertEqual + "Expecting a single relation to be exported." + [[String "foo"]] + . namedRowsRows + . cozoOkayNamedRows + $ o + ] + +runQueryTests :: (HasCallStack) => IO Connection -> TestTree +runQueryTests ioc = + testGroup + "runQuery Tests" + [ testCase "Example Query" $ do + c <- ioc + rs <- + unsafeRows + =<< runQuery c "?[] <- [[1,2,3], ['a', 'b', 'c']]" empty + assertEqual + "Expecting a literal query to return valid results." + [toJSON @Int <$> [1, 2, 3], toJSON @String <$> ["a", "b", "c"]] + rs + , testCase "Parameterized Query" $ do + c <- ioc + rs <- + unsafeRows + =<< runQuery c "?[] <- [[$foo]]" (singleton "foo" (toJSON @String "foo")) + assertEqual "" [[String "foo"]] rs + , testCase "Can Capture Error Messages" $ do + c <- ioc + (Right (CozoResult cr)) <- runQuery c "?[] <- [[1,2,3]" empty + assertBool "Expecting a failure for incorrect query syntax" (isLeft cr) + ] + +unsafeRows :: Either a CozoResult -> IO [[Value]] +unsafeRows (Right (CozoResult (Right (CozoOkay (NamedRows _ rs _) _)))) = pure rs +unsafeRows _ = fail "Failed to extract rows." + +testWithConnection :: (Connection -> IO c) -> IO c +testWithConnection = + bracket + (open "mem" "" "{}" >>= either throwIO pure) + ((() <$) . close)