Simplify URI parameters.

Author: ncruces

README.md

@@ -107,5 +107,5 @@ The Wasm and VFS layers are also tested by running SQLite's
 - [`github.com/mattn/go-sqlite3`](https://pkg.go.dev/github.com/mattn/go-sqlite3)
 - [`github.com/zombiezen/go-sqlite`](https://pkg.go.dev/github.com/zombiezen/go-sqlite)
 
-[^1]: anything else you find in [`go.mod`](./go.mod) is either a test dependency,
+[^1]: anything else you find in `go.mod` is either a test dependency,
       or needed by one of the extensions.

embed/sqlite3.wasm

@@ -15,7 +15,7 @@ The main differences are [file locking](#file-locking) and [WAL mode](write-ahea
 ### File Locking
 
 POSIX advisory locks, which SQLite uses on Unix, are
-[broken by design](https://sqlite.org/src/artifact/2e8b12?ln=1073-1161).
+[broken by design](https://github.com/sqlite/sqlite/blob/b74eb0/src/os_unix.c#L1073-L1161).
 
 On Linux and macOS, this module uses
 [OFD locks](https://www.gnu.org/software/libc/manual/html_node/Open-File-Description-Locks.html)

vfs/README.md

@@ -103,27 +103,32 @@ func (n *Filename) URIParameter(key string) string {
 	}
 
 	uriKey := n.mod.ExportedFunction("sqlite3_uri_key")
-	uriParam := n.mod.ExportedFunction("sqlite3_uri_parameter")
+	n.stack[0] = uint64(n.zPath)
+	n.stack[1] = uint64(0)
+	if err := uriKey.CallWithStack(n.ctx, n.stack[:]); err != nil {
+		panic(err)
+	}
 
-	for i := 0; ; i++ {
-		n.stack[1] = uint64(i)
-		n.stack[0] = uint64(n.zPath)
-		if err := uriKey.CallWithStack(n.ctx, n.stack[:]); err != nil {
-			panic(err)
-		}
-		if n.stack[0] == 0 {
+	ptr := uint32(n.stack[0])
+	if ptr == 0 {
+		return ""
+	}
+
+	// Parse the format from:
+	// https://github.com/sqlite/sqlite/blob/b74eb0/src/pager.c#L4797-L4840
+	// This avoids having to alloc/free the key just to find a value.
+	for {
+		k := util.ReadString(n.mod, ptr, _MAX_NAME)
+		if k == "" {
 			return ""
 		}
-		if key != util.ReadString(n.mod, uint32(n.stack[0]), _MAX_NAME) {
-			continue
-		}
+		ptr += uint32(len(k)) + 1
 
-		n.stack[1] = n.stack[0]
-		n.stack[0] = uint64(n.zPath)
-		if err := uriParam.CallWithStack(n.ctx, n.stack[:]); err != nil {
-			panic(err)
+		v := util.ReadString(n.mod, ptr, _MAX_NAME)
+		if k == key {
+			return v
 		}
-		return util.ReadString(n.mod, uint32(n.stack[0]), _MAX_NAME)
+		ptr += uint32(len(v)) + 1
 	}
 }
 
@@ -135,32 +140,35 @@ func (n *Filename) URIParameters() url.Values {
 		return nil
 	}
 
-	var params url.Values
 	uriKey := n.mod.ExportedFunction("sqlite3_uri_key")
-	uriParam := n.mod.ExportedFunction("sqlite3_uri_parameter")
+	n.stack[0] = uint64(n.zPath)
+	n.stack[1] = uint64(0)
+	if err := uriKey.CallWithStack(n.ctx, n.stack[:]); err != nil {
+		panic(err)
+	}
 
-	for i := 0; ; i++ {
-		n.stack[1] = uint64(i)
-		n.stack[0] = uint64(n.zPath)
-		if err := uriKey.CallWithStack(n.ctx, n.stack[:]); err != nil {
-			panic(err)
-		}
-		if n.stack[0] == 0 {
+	ptr := uint32(n.stack[0])
+	if ptr == 0 {
+		return nil
+	}
+
+	var params url.Values
+
+	// Parse the format from:
+	// https://github.com/sqlite/sqlite/blob/b74eb0/src/pager.c#L4797-L4840
+	// This is the only way to support multiple valued keys.
+	for {
+		k := util.ReadString(n.mod, ptr, _MAX_NAME)
+		if k == "" {
 			return params
 		}
-		key := util.ReadString(n.mod, uint32(n.stack[0]), _MAX_NAME)
-		if params.Has(key) {
-			continue
-		}
+		ptr += uint32(len(k)) + 1
 
-		n.stack[1] = n.stack[0]
-		n.stack[0] = uint64(n.zPath)
-		if err := uriParam.CallWithStack(n.ctx, n.stack[:]); err != nil {
-			panic(err)
-		}
+		v := util.ReadString(n.mod, ptr, _MAX_NAME)
 		if params == nil {
 			params = url.Values{}
 		}
-		params.Set(key, util.ReadString(n.mod, uint32(n.stack[0]), _MAX_NAME))
+		params.Add(k, v)
+		ptr += uint32(len(v)) + 1
 	}
 }

vfs/filename.go

@@ -23,7 +23,7 @@ func (memVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, err
 	// This is not a problem for most SQLite file types:
 	// - databases, which only do page aligned reads/writes;
 	// - temp journals, as used by the sorter, which does the same:
-	//   https://sqlite.org/src/artifact/237840?ln=409-412
+	//   https://github.com/sqlite/sqlite/blob/b74eb0/src/vdbesort.c#L409-L412
 	//
 	// We refuse to open all other file types,
 	// but returning OPEN_MEMORY means SQLite won't ask us to.

vfs/memdb/memdb.go

@@ -2,5 +2,4 @@ aligned_alloc
 free
 malloc
 sqlite3_database_file_object
-sqlite3_uri_key
-sqlite3_uri_parameter
+sqlite3_uri_key

vfs/tests/mptest/testdata/exports.txt

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:3fc3e666b2bb3e0e27622d43ab35f802111c59155c592a7c822f09d1229e8700
-size 470668
+oid sha256:1de925ac1b2a15c0e0ac4231a507d31bdf1ea576f0d768f5f4bf5c3436a1eece
+size 470117

vfs/tests/mptest/testdata/mptest.wasm.bz2

@@ -2,5 +2,4 @@ aligned_alloc
 free
 malloc
 sqlite3_database_file_object
-sqlite3_uri_key
-sqlite3_uri_parameter
+sqlite3_uri_key

vfs/tests/speedtest1/testdata/exports.txt

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:4573183e549df979c07040d92c3b2de72b5dd49ad0d8e779de63ed95fba4e898
-size 484084
+oid sha256:262f1702de606413a92fbb9d7d58b812140d072cacabe79556d5fa38e00461d0
+size 483792