Merge pull request #1 from fluencelabs/add_demo_vfs

Add demo vfs

Config.toml

@@ -2,5 +2,5 @@ modules_dir = "./"
 
 [[module]]
     name = "sqlite3"
-    mem_pages_count = 100
+    mem_pages_count = 1000
     logger_enabled = true

Dockerfile

@@ -4,9 +4,12 @@ RUN apt-get update \
  && apt-get install -y ca-certificates \
                        curl \
                        git \
-                       make
+                       make \
+                       cargo
 
-RUN curl -L https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-10/wasi-sdk-10.0-linux.tar.gz | tar xz --strip-components=1 -C /
+RUN curl -L https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-11/wasi-sdk-11.0-linux.tar.gz | tar xz --strip-components=1 -C /
+
+RUN cargo install fcli --version 0.1.12
 
 VOLUME /code
 WORKDIR /code

Makefile

@@ -2,8 +2,9 @@ TARGET = sqlite3
 CC = /bin/clang
 SYSROOT = /share/wasi-sysroot
 TARGET_TRIPLE = wasm32-wasi
-CFLAGS = -nostartfiles -fvisibility=hidden
-LDFLAGS = -Wl,--no-entry,--demangle,--allow-undefined
+CFLAGS = -fvisibility=hidden
+SDK = sdk/logger.h
+LDFLAGS = -Wl,--demangle,--allow-undefined
 EXPORT_FUNCS = \
 	--export=allocate,$\
 	--export=deallocate,$\
@@ -11,7 +12,32 @@ EXPORT_FUNCS = \
 	--export=set_result_ptr,$\
 	--export=get_result_size,$\
 	--export=get_result_ptr,$\
-	--export=invoke
+	--export=sqlite3_open_v2_,$\
+	--export=sqlite3_close,$\
+	--export=sqlite3_prepare_v2_,$\
+	--export=sqlite3_exec_,$\
+	--export=sqlite3_libversion_number,$\
+	--export=sqlite3_total_changes,$\
+	--export=sqlite3_changes,$\
+	--export=sqlite3_busy_timeout,$\
+	--export=sqlite3_errmsg_,$\
+	--export=sqlite3_errcode,$\
+	--export=sqlite3_column_type,$\
+	--export=sqlite3_column_name_,$\
+	--export=sqlite3_step,$\
+	--export=sqlite3_reset,$\
+	--export=sqlite3_bind_blob_,$\
+	--export=sqlite3_bind_double,$\
+	--export=sqlite3_bind_int64,$\
+	--export=sqlite3_bind_text_,$\
+	--export=sqlite3_bind_null,$\
+	--export=sqlite3_column_count,$\
+	--export=sqlite3_column_double,$\
+	--export=sqlite3_column_int64,$\
+	--export=sqlite3_column_text_,$\
+	--export=sqlite3_column_blob_,$\
+	--export=sqlite3_column_bytes,$\
+	--export=sqlite3_finalize
 SQLITE_SRC = \
 	src/alter.c\
 	src/analyze.c\
@@ -26,6 +52,8 @@ SQLITE_SRC = \
 	src/complete.c\
 	src/ctime.c\
 	src/date.c\
+	src/demo_os.c\
+	src/demo_vfs.c\
 	src/dbpage.c\
 	src/dbstat.c\
 	src/delete.c\
@@ -110,6 +138,7 @@ SQLITE_FLAGS = \
 	-DENABLE_LOG\
 	-DBUILD_sqlite\
 	-DNDEBUG\
+	-DSQLITE_OS_UNIX\
 	-DSQLITE_THREADSAFE=0\
 	-DHAVE_READLINE=0\
 	-DHAVE_EDITLINE=0\
@@ -134,6 +163,7 @@ all: default
 
 $(TARGET): $(SQLITE_SRC) $(WRAPPER_SRC)
 	$(CC) -O3 --sysroot=$(SYSROOT) --target=$(TARGET_TRIPLE) $(SQLITE_FLAGS) $(CFLAGS) $(LDFLAGS) -Wl,$(EXPORT_FUNCS) $^ -o $@.wasm
+	/root/.cargo/bin/fce embed -i sqlite3.wasm -w sqlite3.wit
 
 .PRECIOUS: $(TARGET)
 

sqlite3.wit

@@ -1,43 +1,458 @@
-;; Fluence SQLite fork Wasm Interface Types
+;; Types
+(@interface type (func
+  (param $size: i32)
+  (result i32)))   ;; 0
+(@interface type (func
+  (param $pointer: i32 $size: i32) ))   ;; 1
+(@interface type (func
+  (result i32)))   ;; 2
+(@interface type (func
+  (result i32)))   ;; 3
+(@interface type (func
+  (param $result_size: i32) ))   ;; 4
+(@interface type (func
+  (param $result_ptr: i32) ))   ;; 5
+(@interface type (record $DBExecDescriptor (
+ field $ret_code: s32
+ field $err_msg: string
+)))   ;; 6
+(@interface type (record $DBPrepareDescriptor (
+ field $ret_code: s32
+ field $stmt_handle: u32
+ field $tail: u32
+)))   ;; 7
+(@interface type (record $DBOpenDescriptor (
+ field $ret_code: s32
+ field $db_handle: u32
+)))   ;; 8
+(@interface type (func
+  (param $stmt_handle: u32 $icol: u32)
+  (result string)))   ;; 9
+(@interface type (func
+  (param $stmt_handle: u32 $icol: u32)
+  (result string)))   ;; 10
+(@interface type (func
+  (param $stmt_handle: u32 $icol: u32)
+  (result s32)))   ;; 11
+(@interface type (func
+  (param $stmt_handle: u32 $icol: u32)
+  (result s32)))   ;; 12
+(@interface type (func
+  (param $db_handle: u32)
+  (result s32)))   ;; 13
+(@interface type (func
+  (param $db_handle: u32)
+  (result s32)))   ;; 14
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32 $value: f64)
+  (result s32)))   ;; 15
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32 $value: f64)
+  (result s32)))   ;; 16
+(@interface type (func
+  (param $filename: string $flags: s32 $vfs: string)
+  (result record 8)))   ;; 17
+(@interface type (func
+  (param $filename: string $flags: s32 $vfs: string)
+  (result record 8)))   ;; 18
+(@interface type (func
+  (param $db_handle: u32)
+  (result s32)))   ;; 19
+(@interface type (func
+  (param $db_handle: u32)
+  (result s32)))   ;; 20
+(@interface type (func
+  (param $stmt_handle: u32)
+  (result s32)))   ;; 21
+(@interface type (func
+  (param $stmt_handle: u32)
+  (result s32)))   ;; 22
+(@interface type (func
+  (param $stmt_handle: u32 $icol: u32)
+  (result s64)))   ;; 23
+(@interface type (func
+  (param $stmt_handle: u32 $icol: u32)
+  (result s64)))   ;; 24
+(@interface type (func
+  (param $db: u32)
+  (result s32)))   ;; 25
+(@interface type (func
+  (param $db: u32)
+  (result s32)))   ;; 26
+(@interface type (func
+  (param $stmt_handle: u32 $icol: s32)
+  (result f64)))   ;; 27
+(@interface type (func
+  (param $stmt_handle: u32 $icol: s32)
+  (result f64)))   ;; 28
+(@interface type (func
+  (param $db_handle: u32 $ms: u32)
+  (result s32)))   ;; 29
+(@interface type (func
+  (param $db_handle: u32 $ms: u32)
+  (result s32)))   ;; 30
+(@interface type (func
+  (param $db_handle: u32)
+  (result string)))   ;; 31
+(@interface type (func
+  (param $db_handle: u32)
+  (result string)))   ;; 32
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32 $value: s64)
+  (result s32)))   ;; 33
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32 $value: s64)
+  (result s32)))   ;; 34
+(@interface type (func
+  (param $stmt_handle: u32)
+  (result s32)))   ;; 35
+(@interface type (func
+  (param $stmt_handle: u32)
+  (result s32)))   ;; 36
+(@interface type (func
+  (param $db_handle: u32 $sql: string)
+  (result record 7)))   ;; 37
+(@interface type (func
+  (param $db_handle: u32 $sql: string)
+  (result record 7)))   ;; 38
+(@interface type (func
+  (param $stmt_handle: u32)
+  (result s32)))   ;; 39
+(@interface type (func
+  (param $stmt_handle: u32)
+  (result s32)))   ;; 40
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32)
+  (result s32)))   ;; 41
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32)
+  (result s32)))   ;; 42
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32 $blob: array (u8) $xDel: s32)
+  (result s32)))   ;; 43
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32 $blob: array (u8) $xDel: s32)
+  (result s32)))   ;; 44
+(@interface type (func
+  (param $db_handle: u32)
+  (result s32)))   ;; 45
+(@interface type (func
+  (param $db_handle: u32)
+  (result s32)))   ;; 46
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32 $text: string $xDel: s32)
+  (result s32)))   ;; 47
+(@interface type (func
+  (param $stmt_handle: u32 $pos: s32 $text: string $xDel: s32)
+  (result s32)))   ;; 48
+(@interface type (func
+  (param $stmt_handle: u32)
+  (result s32)))   ;; 49
+(@interface type (func
+  (param $stmt_handle: u32)
+  (result s32)))   ;; 50
+(@interface type (func
+  (param $db_handle: u32 $sql: string $callback_id: s32 $callback_arg: s32)
+  (result record 6)))   ;; 51
+(@interface type (func
+  (param $db_handle: u32 $sql: string $callback_id: s32 $callback_arg: s32)
+  (result record 6)))   ;; 52
+(@interface type (func
+  (result s32)))   ;; 53
+(@interface type (func
+  (result s32)))   ;; 54
+(@interface type (func
+  (param $stmt_handle: u32 $icol: s32)
+  (result array (u8))))   ;; 55
+(@interface type (func
+  (param $stmt_handle: u32 $icol: s32)
+  (result array (u8))))   ;; 56
+(@interface type (func
+  (param $stmt_handle: u32 $N: u32)
+  (result string)))   ;; 57
+(@interface type (func
+  (param $stmt_handle: u32 $N: u32)
+  (result string)))   ;; 58
+(@interface type (func
+  (param $stmt_handle: u32 $icol: u32)
+  (result s32)))   ;; 59
+(@interface type (func
+  (param $stmt_handle: u32 $icol: u32)
+  (result s32)))   ;; 60
 
-;; allocate
-(@interface type (func (param $size: i32) (result i32)))                ;; 0
 
-;; deallocate
-(@interface type (func (param $pointer: i32 $size: i32)))               ;; 1
 
-;; invoke
-(@interface type (func (param $request: string) (result string)))       ;; 2
+;; Adapters
+(@interface func (type 9)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_u32
+  call-core 6
+  call-core 3
+  call-core 2
+  string.lift_memory
+  call-core 3
+  call-core 2
+  call-core 1)
+(@interface func (type 11)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_u32
+  call-core 7
+  s32.from_i32)
+(@interface func (type 13)
+  arg.get 0
+  i32.from_u32
+  call-core 8
+  s32.from_i32)
+(@interface func (type 15)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_s32
+  arg.get 2
+  call-core 9
+  s32.from_i32)
+(@interface func (type 17)
+  arg.get 0
+  string.size
+  call-core 0
+  arg.get 0
+  string.lower_memory
+  arg.get 1
+  i32.from_s32
+  arg.get 2
+  string.size
+  call-core 0
+  arg.get 2
+  string.lower_memory
+  call-core 10
+  call-core 3
+  record.lift_memory 8)
+(@interface func (type 19)
+  arg.get 0
+  i32.from_u32
+  call-core 11
+  s32.from_i32)
+(@interface func (type 21)
+  arg.get 0
+  i32.from_u32
+  call-core 12
+  s32.from_i32)
+(@interface func (type 23)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_u32
+  call-core 13
+  s64.from_i64)
+(@interface func (type 25)
+  arg.get 0
+  i32.from_u32
+  call-core 14
+  s32.from_i32)
+(@interface func (type 27)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_s32
+  call-core 15)
+(@interface func (type 29)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_u32
+  call-core 16
+  s32.from_i32)
+(@interface func (type 31)
+  arg.get 0
+  i32.from_u32
+  call-core 17
+  call-core 3
+  call-core 2
+  string.lift_memory
+  call-core 3
+  call-core 2
+  call-core 1)
+(@interface func (type 33)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_s32
+  arg.get 2
+  i64.from_s64
+  call-core 18
+  s32.from_i32)
+(@interface func (type 35)
+  arg.get 0
+  i32.from_u32
+  call-core 19
+  s32.from_i32)
+(@interface func (type 37)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  string.size
+  call-core 0
+  arg.get 1
+  string.lower_memory
+  call-core 20
+  call-core 3
+  record.lift_memory 7)
+(@interface func (type 39)
+  arg.get 0
+  i32.from_u32
+  call-core 21
+  s32.from_i32)
+(@interface func (type 41)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_s32
+  call-core 22
+  s32.from_i32)
+(@interface func (type 43)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_s32
+  arg.get 2
+  array.lower_memory u8
+  arg.get 3
+  i32.from_s32
+  call-core 23
+  s32.from_i32)
+(@interface func (type 45)
+  arg.get 0
+  i32.from_u32
+  call-core 24
+  s32.from_i32)
+(@interface func (type 47)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_s32
+  arg.get 2
+  string.size
+  call-core 0
+  arg.get 2
+  string.lower_memory
+  arg.get 3
+  i32.from_s32
+  call-core 25
+  s32.from_i32)
+(@interface func (type 49)
+  arg.get 0
+  i32.from_u32
+  call-core 26
+  s32.from_i32)
+(@interface func (type 51)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  string.size
+  call-core 0
+  arg.get 1
+  string.lower_memory
+  arg.get 2
+  i32.from_s32
+  arg.get 3
+  i32.from_s32
+  call-core 27
+  call-core 3
+  record.lift_memory 6)
+(@interface func (type 53)
+  call-core 28
+  s32.from_i32)
+(@interface func (type 55)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_s32
+  call-core 29
+  call-core 3
+  call-core 2
+  array.lift_memory u8)
+(@interface func (type 57)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_u32
+  call-core 30
+  call-core 3
+  call-core 2
+  string.lift_memory
+  call-core 3
+  call-core 2
+  call-core 1)
+(@interface func (type 59)
+  arg.get 0
+  i32.from_u32
+  arg.get 1
+  i32.from_u32
+  call-core 31
+  s32.from_i32)
 
-;; get_result_ptr/get_result_size
-(@interface type (func (result i32)))                                   ;; 3
-
-;; set_result_ptr/set_result_size
-(@interface type (func (param $result: i32)))                           ;; 4
-
-(@interface export "allocate" (func  0))               ;; 0
-(@interface export "deallocate" (func 1))              ;; 1
-(@interface export "invoke" (func 2))                  ;; 2
-(@interface export "get_result_size" (func 3))         ;; 3
-(@interface export "get_result_ptr" (func 3))          ;; 4
-(@interface export "set_result_size" (func 4))         ;; 5
-(@interface export "set_result_ptr" (func 4))          ;; 6
-
-;; adapter for export invoke function
-(@interface func (type 2)
-    arg.get 0
-    string.size
-    call-core 0             ;; call allocate
-    arg.get 0
-    string.lower_memory
-    call-core 2             ;; call invoke
-    call-core 4             ;; call get_result_size
-    call-core 3             ;; call get_result_ptr
-    string.lift_memory
-    call-core 4             ;; call get_result_size
-    call-core 3             ;; call get_result_ptr
-    call-core 1             ;; call deallocate
-)
+;; Exports
+(@interface export "allocate" (func 0))
+(@interface export "deallocate" (func 1))
+(@interface export "get_result_size" (func 2))
+(@interface export "get_result_ptr" (func 3))
+(@interface export "set_result_size" (func 4))
+(@interface export "set_result_ptr" (func 5))
+(@interface export "sqlite3_column_text" (func 10))
+(@interface export "sqlite3_column_bytes" (func 12))
+(@interface export "sqlite3_close" (func 14))
+(@interface export "sqlite3_bind_double" (func 16))
+(@interface export "sqlite3_open_v2" (func 18))
+(@interface export "sqlite3_changes" (func 20))
+(@interface export "sqlite3_step" (func 22))
+(@interface export "sqlite3_column_int64" (func 24))
+(@interface export "sqlite3_errcode" (func 26))
+(@interface export "sqlite3_column_double" (func 28))
+(@interface export "sqlite3_busy_timeout" (func 30))
+(@interface export "sqlite3_errmsg" (func 32))
+(@interface export "sqlite3_bind_int64" (func 34))
+(@interface export "sqlite3_finalize" (func 36))
+(@interface export "sqlite3_prepare_v2" (func 38))
+(@interface export "sqlite3_column_count" (func 40))
+(@interface export "sqlite3_bind_null" (func 42))
+(@interface export "sqlite3_bind_blob" (func 44))
+(@interface export "sqlite3_total_changes" (func 46))
+(@interface export "sqlite3_bind_text" (func 48))
+(@interface export "sqlite3_reset" (func 50))
+(@interface export "sqlite3_exec" (func 52))
+(@interface export "sqlite3_libversion_number" (func 54))
+(@interface export "sqlite3_column_blob" (func 56))
+(@interface export "sqlite3_column_name" (func 58))
+(@interface export "sqlite3_column_type" (func 60))
 
 ;; Implementations
-(@interface implement (func 2) (func 2))
+(@interface implement (func 10) (func 9))
+(@interface implement (func 12) (func 11))
+(@interface implement (func 14) (func 13))
+(@interface implement (func 16) (func 15))
+(@interface implement (func 18) (func 17))
+(@interface implement (func 20) (func 19))
+(@interface implement (func 22) (func 21))
+(@interface implement (func 24) (func 23))
+(@interface implement (func 26) (func 25))
+(@interface implement (func 28) (func 27))
+(@interface implement (func 30) (func 29))
+(@interface implement (func 32) (func 31))
+(@interface implement (func 34) (func 33))
+(@interface implement (func 36) (func 35))
+(@interface implement (func 38) (func 37))
+(@interface implement (func 40) (func 39))
+(@interface implement (func 42) (func 41))
+(@interface implement (func 44) (func 43))
+(@interface implement (func 46) (func 45))
+(@interface implement (func 48) (func 47))
+(@interface implement (func 50) (func 49))
+(@interface implement (func 52) (func 51))
+(@interface implement (func 54) (func 53))
+(@interface implement (func 56) (func 55))
+(@interface implement (func 58) (func 57))
+(@interface implement (func 60) (func 59))

src/demo_os.c

@@ -0,0 +1,12 @@
+#include "sqlite3.h"
+
+extern sqlite3_vfs *sqlite3_demovfs(void);
+
+int sqlite3_os_init() {
+  sqlite3_vfs_register(sqlite3_demovfs(), 0);
+  return SQLITE_OK;
+}
+
+int sqlite3_os_end() {
+  return SQLITE_OK;
+}

src/demo_vfs.c

@@ -0,0 +1,679 @@
+/*
+** 2010 April 7
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file implements an example of a simple VFS implementation that
+** omits complex features often not required or not possible on embedded
+** platforms.  Code is included to buffer writes to the journal file,
+** which can be a significant performance improvement on some embedded
+** platforms.
+**
+** OVERVIEW
+**
+**   The code in this file implements a minimal SQLite VFS that can be
+**   used on Linux and other posix-like operating systems. The following
+**   system calls are used:
+**
+**    File-system: access(), unlink(), getcwd()
+**    File IO:     open(), read(), write(), fsync(), close(), fstat()
+**    Other:       sleep(), usleep(), time()
+**
+**   The following VFS features are omitted:
+**
+**     1. File locking. The user must ensure that there is at most one
+**        connection to each database when using this VFS. Multiple
+**        connections to a single shared-cache count as a single connection
+**        for the purposes of the previous statement.
+**
+**     2. The loading of dynamic extensions (shared libraries).
+**
+**     3. Temporary files. The user must configure SQLite to use in-memory
+**        temp files when using this VFS. The easiest way to do this is to
+**        compile with:
+**
+**          -DSQLITE_TEMP_STORE=3
+**
+**     4. File truncation. As of version 3.6.24, SQLite may run without
+**        a working xTruncate() call, providing the user does not configure
+**        SQLite to use "journal_mode=truncate", or use both
+**        "journal_mode=persist" and ATTACHed databases.
+**
+**   It is assumed that the system uses UNIX-like path-names. Specifically,
+**   that '/' characters are used to separate path components and that
+**   a path-name is a relative path unless it begins with a '/'. And that
+**   no UTF-8 encoded paths are greater than 512 bytes in length.
+**
+** JOURNAL WRITE-BUFFERING
+**
+**   To commit a transaction to the database, SQLite first writes rollback
+**   information into the journal file. This usually consists of 4 steps:
+**
+**     1. The rollback information is sequentially written into the journal
+**        file, starting at the start of the file.
+**     2. The journal file is synced to disk.
+**     3. A modification is made to the first few bytes of the journal file.
+**     4. The journal file is synced to disk again.
+**
+**   Most of the data is written in step 1 using a series of calls to the
+**   VFS xWrite() method. The buffers passed to the xWrite() calls are of
+**   various sizes. For example, as of version 3.6.24, when committing a
+**   transaction that modifies 3 pages of a database file that uses 4096
+**   byte pages residing on a media with 512 byte sectors, SQLite makes
+**   eleven calls to the xWrite() method to create the rollback journal,
+**   as follows:
+**
+**             Write offset | Bytes written
+**             ----------------------------
+**                        0            512
+**                      512              4
+**                      516           4096
+**                     4612              4
+**                     4616              4
+**                     4620           4096
+**                     8716              4
+**                     8720              4
+**                     8724           4096
+**                    12820              4
+**             ++++++++++++SYNC+++++++++++
+**                        0             12
+**             ++++++++++++SYNC+++++++++++
+**
+**   On many operating systems, this is an efficient way to write to a file.
+**   However, on some embedded systems that do not cache writes in OS
+**   buffers it is much more efficient to write data in blocks that are
+**   an integer multiple of the sector-size in size and aligned at the
+**   start of a sector.
+**
+**   To work around this, the code in this file allocates a fixed size
+**   buffer of SQLITE_DEMOVFS_BUFFERSZ using sqlite3_malloc() whenever a
+**   journal file is opened. It uses the buffer to coalesce sequential
+**   writes into aligned SQLITE_DEMOVFS_BUFFERSZ blocks. When SQLite
+**   invokes the xSync() method to sync the contents of the file to disk,
+**   all accumulated data is written out, even if it does not constitute
+**   a complete block. This means the actual IO to create the rollback
+**   journal for the example transaction above is this:
+**
+**             Write offset | Bytes written
+**             ----------------------------
+**                        0           8192
+**                     8192           4632
+**             ++++++++++++SYNC+++++++++++
+**                        0             12
+**             ++++++++++++SYNC+++++++++++
+**
+**   Much more efficient if the underlying OS is not caching write
+**   operations.
+*/
+
+#if !defined(SQLITE_TEST) || SQLITE_OS_UNIX
+
+#include "sqlite3.h"
+
+#include <assert.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/file.h>
+#include <sys/param.h>
+#include <unistd.h>
+#include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+
+/*
+** Size of the write buffer used by journal files in bytes.
+*/
+#ifndef SQLITE_DEMOVFS_BUFFERSZ
+# define SQLITE_DEMOVFS_BUFFERSZ 8192
+#endif
+
+/*
+** The maximum pathname length supported by this VFS.
+*/
+#define MAXPATHNAME 512
+
+/*
+** When using this VFS, the sqlite3_file* handles that SQLite uses are
+** actually pointers to instances of type DemoFile.
+*/
+typedef struct DemoFile DemoFile;
+struct DemoFile {
+  sqlite3_file base;              /* Base class. Must be first. */
+  int fd;                         /* File descriptor */
+
+  char *aBuffer;                  /* Pointer to malloc'd buffer */
+  int nBuffer;                    /* Valid bytes of data in zBuffer */
+  sqlite3_int64 iBufferOfst;      /* Offset in file of zBuffer[0] */
+};
+
+/*
+** Write directly to the file passed as the first argument. Even if the
+** file has a write-buffer (DemoFile.aBuffer), ignore it.
+*/
+static int demoDirectWrite(
+  DemoFile *p,                    /* File handle */
+  const void *zBuf,               /* Buffer containing data to write */
+  int iAmt,                       /* Size of data to write in bytes */
+  sqlite_int64 iOfst              /* File offset to write to */
+){
+  off_t ofst;                     /* Return value from lseek() */
+  size_t nWrite;                  /* Return value from write() */
+
+  ofst = lseek(p->fd, iOfst, SEEK_SET);
+  if( ofst!=iOfst ){
+    return SQLITE_IOERR_WRITE;
+  }
+
+  nWrite = write(p->fd, zBuf, iAmt);
+  if( nWrite!=iAmt ){
+    return SQLITE_IOERR_WRITE;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Flush the contents of the DemoFile.aBuffer buffer to disk. This is a
+** no-op if this particular file does not have a buffer (i.e. it is not
+** a journal file) or if the buffer is currently empty.
+*/
+static int demoFlushBuffer(DemoFile *p){
+  int rc = SQLITE_OK;
+  if( p->nBuffer ){
+    rc = demoDirectWrite(p, p->aBuffer, p->nBuffer, p->iBufferOfst);
+    p->nBuffer = 0;
+  }
+  return rc;
+}
+
+/*
+** Close a file.
+*/
+static int demoClose(sqlite3_file *pFile){
+  int rc;
+  DemoFile *p = (DemoFile*)pFile;
+  rc = demoFlushBuffer(p);
+  sqlite3_free(p->aBuffer);
+  close(p->fd);
+  return rc;
+}
+
+/*
+** Read data from a file.
+*/
+static int demoRead(
+  sqlite3_file *pFile,
+  void *zBuf,
+  int iAmt,
+  sqlite_int64 iOfst
+){
+  DemoFile *p = (DemoFile*)pFile;
+  off_t ofst;                     /* Return value from lseek() */
+  int nRead;                      /* Return value from read() */
+  int rc;                         /* Return code from demoFlushBuffer() */
+
+  /* Flush any data in the write buffer to disk in case this operation
+  ** is trying to read data the file-region currently cached in the buffer.
+  ** It would be possible to detect this case and possibly save an
+  ** unnecessary write here, but in practice SQLite will rarely read from
+  ** a journal file when there is data cached in the write-buffer.
+  */
+  rc = demoFlushBuffer(p);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  ofst = lseek(p->fd, iOfst, SEEK_SET);
+  if( ofst!=iOfst ){
+    return SQLITE_IOERR_READ;
+  }
+  nRead = read(p->fd, zBuf, iAmt);
+
+  if( nRead==iAmt ){
+    return SQLITE_OK;
+  }else if( nRead>=0 ){
+    return SQLITE_IOERR_SHORT_READ;
+  }
+
+  return SQLITE_IOERR_READ;
+}
+
+/*
+** Write data to a crash-file.
+*/
+static int demoWrite(
+  sqlite3_file *pFile,
+  const void *zBuf,
+  int iAmt,
+  sqlite_int64 iOfst
+){
+  DemoFile *p = (DemoFile*)pFile;
+
+  if( p->aBuffer ){
+    char *z = (char *)zBuf;       /* Pointer to remaining data to write */
+    int n = iAmt;                 /* Number of bytes at z */
+    sqlite3_int64 i = iOfst;      /* File offset to write to */
+
+    while( n>0 ){
+      int nCopy;                  /* Number of bytes to copy into buffer */
+
+      /* If the buffer is full, or if this data is not being written directly
+      ** following the data already buffered, flush the buffer. Flushing
+      ** the buffer is a no-op if it is empty.
+      */
+      if( p->nBuffer==SQLITE_DEMOVFS_BUFFERSZ || p->iBufferOfst+p->nBuffer!=i ){
+        int rc = demoFlushBuffer(p);
+        if( rc!=SQLITE_OK ){
+          return rc;
+        }
+      }
+      assert( p->nBuffer==0 || p->iBufferOfst+p->nBuffer==i );
+      p->iBufferOfst = i - p->nBuffer;
+
+      /* Copy as much data as possible into the buffer. */
+      nCopy = SQLITE_DEMOVFS_BUFFERSZ - p->nBuffer;
+      if( nCopy>n ){
+        nCopy = n;
+      }
+      memcpy(&p->aBuffer[p->nBuffer], z, nCopy);
+      p->nBuffer += nCopy;
+
+      n -= nCopy;
+      i += nCopy;
+      z += nCopy;
+    }
+  }else{
+    return demoDirectWrite(p, zBuf, iAmt, iOfst);
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Truncate a file. This is a no-op for this VFS (see header comments at
+** the top of the file).
+*/
+static int demoTruncate(sqlite3_file *pFile, sqlite_int64 size){
+#if 0
+  if( ftruncate(((DemoFile *)pFile)->fd, size) ) return SQLITE_IOERR_TRUNCATE;
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** Sync the contents of the file to the persistent media.
+*/
+static int demoSync(sqlite3_file *pFile, int flags){
+  DemoFile *p = (DemoFile*)pFile;
+  int rc;
+
+  rc = demoFlushBuffer(p);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  rc = fsync(p->fd);
+  return (rc==0 ? SQLITE_OK : SQLITE_IOERR_FSYNC);
+}
+
+/*
+** Write the size of the file in bytes to *pSize.
+*/
+static int demoFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  DemoFile *p = (DemoFile*)pFile;
+  int rc;                         /* Return code from fstat() call */
+  struct stat sStat;              /* Output of fstat() call */
+
+  /* Flush the contents of the buffer to disk. As with the flush in the
+  ** demoRead() method, it would be possible to avoid this and save a write
+  ** here and there. But in practice this comes up so infrequently it is
+  ** not worth the trouble.
+  */
+  rc = demoFlushBuffer(p);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  rc = fstat(p->fd, &sStat);
+  if( rc!=0 ) return SQLITE_IOERR_FSTAT;
+  *pSize = sStat.st_size;
+  return SQLITE_OK;
+}
+
+/*
+** Locking functions. The xLock() and xUnlock() methods are both no-ops.
+** The xCheckReservedLock() always indicates that no other process holds
+** a reserved lock on the database file. This ensures that if a hot-journal
+** file is found in the file-system it is rolled back.
+*/
+static int demoLock(sqlite3_file *pFile, int eLock){
+  return SQLITE_OK;
+}
+static int demoUnlock(sqlite3_file *pFile, int eLock){
+  return SQLITE_OK;
+}
+static int demoCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  *pResOut = 0;
+  return SQLITE_OK;
+}
+
+/*
+** No xFileControl() verbs are implemented by this VFS.
+*/
+static int demoFileControl(sqlite3_file *pFile, int op, void *pArg){
+  return SQLITE_OK;
+}
+
+/*
+** The xSectorSize() and xDeviceCharacteristics() methods. These two
+** may return special values allowing SQLite to optimize file-system
+** access to some extent. But it is also safe to simply return 0.
+*/
+static int demoSectorSize(sqlite3_file *pFile){
+  return 0;
+}
+static int demoDeviceCharacteristics(sqlite3_file *pFile){
+  return 0;
+}
+
+/*
+** Open a file handle.
+*/
+static int demoOpen(
+  sqlite3_vfs *pVfs,              /* VFS */
+  const char *zName,              /* File to open, or 0 for a temp file */
+  sqlite3_file *pFile,            /* Pointer to DemoFile struct to populate */
+  int flags,                      /* Input SQLITE_OPEN_XXX flags */
+  int *pOutFlags                  /* Output SQLITE_OPEN_XXX flags (or NULL) */
+){
+  static const sqlite3_io_methods demoio = {
+    1,                            /* iVersion */
+    demoClose,                    /* xClose */
+    demoRead,                     /* xRead */
+    demoWrite,                    /* xWrite */
+    demoTruncate,                 /* xTruncate */
+    demoSync,                     /* xSync */
+    demoFileSize,                 /* xFileSize */
+    demoLock,                     /* xLock */
+    demoUnlock,                   /* xUnlock */
+    demoCheckReservedLock,        /* xCheckReservedLock */
+    demoFileControl,              /* xFileControl */
+    demoSectorSize,               /* xSectorSize */
+    demoDeviceCharacteristics     /* xDeviceCharacteristics */
+  };
+
+  DemoFile *p = (DemoFile*)pFile; /* Populate this structure */
+  int oflags = 0;                 /* flags to pass to open() call */
+  char *aBuf = 0;
+
+  if( zName==0 ){
+    return SQLITE_IOERR;
+  }
+
+  if( flags&SQLITE_OPEN_MAIN_JOURNAL ){
+    aBuf = (char *)sqlite3_malloc(SQLITE_DEMOVFS_BUFFERSZ);
+    if( !aBuf ){
+      return SQLITE_NOMEM;
+    }
+  }
+
+  if( flags&SQLITE_OPEN_EXCLUSIVE ) oflags |= O_EXCL;
+  if( flags&SQLITE_OPEN_CREATE )    oflags |= O_CREAT;
+  if( flags&SQLITE_OPEN_READONLY )  oflags |= O_RDONLY;
+  if( flags&SQLITE_OPEN_READWRITE ) oflags |= O_RDWR;
+
+  memset(p, 0, sizeof(DemoFile));
+  p->fd = open(zName, oflags, 0600);
+  if( p->fd<0 ){
+    sqlite3_free(aBuf);
+    return SQLITE_CANTOPEN;
+  }
+  p->aBuffer = aBuf;
+
+  if( pOutFlags ){
+    *pOutFlags = flags;
+  }
+  p->base.pMethods = &demoio;
+  return SQLITE_OK;
+}
+
+/*
+** Delete the file identified by argument zPath. If the dirSync parameter
+** is non-zero, then ensure the file-system modification to delete the
+** file has been synced to disk before returning.
+*/
+static int demoDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  int rc;                         /* Return code */
+
+  rc = unlink(zPath);
+  if( rc!=0 && errno==ENOENT ) return SQLITE_OK;
+
+  if( rc==0 && dirSync ){
+    int dfd;                      /* File descriptor open on directory */
+    int i;                        /* Iterator variable */
+    char zDir[MAXPATHNAME+1];     /* Name of directory containing file zPath */
+
+    /* Figure out the directory name from the path of the file deleted. */
+    sqlite3_snprintf(MAXPATHNAME, zDir, "%s", zPath);
+    zDir[MAXPATHNAME] = '\0';
+    for(i=strlen(zDir); i>1 && zDir[i]!='/'; i++);
+    zDir[i] = '\0';
+
+    /* Open a file-descriptor on the directory. Sync. Close. */
+    dfd = open(zDir, O_RDONLY, 0);
+    if( dfd<0 ){
+      rc = -1;
+    }else{
+      rc = fsync(dfd);
+      close(dfd);
+    }
+  }
+  return (rc==0 ? SQLITE_OK : SQLITE_IOERR_DELETE);
+}
+
+#ifndef F_OK
+# define F_OK 0
+#endif
+#ifndef R_OK
+# define R_OK 4
+#endif
+#ifndef W_OK
+# define W_OK 2
+#endif
+
+/*
+** Query the file-system to see if the named file exists, is readable or
+** is both readable and writable.
+*/
+static int demoAccess(
+  sqlite3_vfs *pVfs,
+  const char *zPath,
+  int flags,
+  int *pResOut
+){
+  int rc;                         /* access() return code */
+  int eAccess = F_OK;             /* Second argument to access() */
+
+  assert( flags==SQLITE_ACCESS_EXISTS       /* access(zPath, F_OK) */
+          || flags==SQLITE_ACCESS_READ         /* access(zPath, R_OK) */
+          || flags==SQLITE_ACCESS_READWRITE    /* access(zPath, R_OK|W_OK) */
+  );
+
+  if( flags==SQLITE_ACCESS_READWRITE ) eAccess = R_OK|W_OK;
+  if( flags==SQLITE_ACCESS_READ )      eAccess = R_OK;
+
+  rc = access(zPath, eAccess);
+  *pResOut = (rc==0);
+  return SQLITE_OK;
+}
+
+/*
+** Argument zPath points to a nul-terminated string containing a file path.
+** If zPath is an absolute path, then it is copied as is into the output
+** buffer. Otherwise, if it is a relative path, then the equivalent full
+** path is written to the output buffer.
+**
+** This function assumes that paths are UNIX style. Specifically, that:
+**
+**   1. Path components are separated by a '/'. and
+**   2. Full paths begin with a '/' character.
+*/
+static int demoFullPathname(
+  sqlite3_vfs *pVfs,              /* VFS */
+  const char *zPath,              /* Input path (possibly a relative path) */
+  int nPathOut,                   /* Size of output buffer in bytes */
+  char *zPathOut                  /* Pointer to output buffer */
+){
+  sqlite3_snprintf(nPathOut, zPathOut, "%s", zPath);
+  zPathOut[nPathOut-1] = '\0';
+
+  return SQLITE_OK;
+}
+
+/*
+** The following four VFS methods:
+**
+**   xDlOpen
+**   xDlError
+**   xDlSym
+**   xDlClose
+**
+** are supposed to implement the functionality needed by SQLite to load
+** extensions compiled as shared objects. This simple VFS does not support
+** this functionality, so the following functions are no-ops.
+*/
+static void *demoDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+  return 0;
+}
+static void demoDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
+  sqlite3_snprintf(nByte, zErrMsg, "Loadable extensions are not supported");
+  zErrMsg[nByte-1] = '\0';
+}
+static void (*demoDlSym(sqlite3_vfs *pVfs, void *pH, const char *z))(void){
+  return 0;
+}
+static void demoDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  return;
+}
+
+/*
+** Parameter zByte points to a buffer nByte bytes in size. Populate this
+** buffer with pseudo-random data.
+*/
+static int demoRandomness(sqlite3_vfs *pVfs, int nByte, char *zByte){
+  return SQLITE_OK;
+}
+
+/*
+** Sleep for at least nMicro microseconds. Return the (approximate) number
+** of microseconds slept for.
+*/
+static int demoSleep(sqlite3_vfs *pVfs, int nMicro){
+  sleep(nMicro / 1000000);
+  usleep(nMicro % 1000000);
+  return nMicro;
+}
+
+/*
+** Set *pTime to the current UTC time expressed as a Julian day. Return
+** SQLITE_OK if successful, or an error code otherwise.
+**
+**   http://en.wikipedia.org/wiki/Julian_day
+**
+** This implementation is not very good. The current time is rounded to
+** an integer number of seconds. Also, assuming time_t is a signed 32-bit
+** value, it will stop working some time in the year 2038 AD (the so-called
+** "year 2038" problem that afflicts systems that store time this way).
+*/
+static int demoCurrentTime(sqlite3_vfs *pVfs, double *pTime){
+  time_t t = time(0);
+  *pTime = t/86400.0 + 2440587.5;
+  return SQLITE_OK;
+}
+
+/*
+** This function returns a pointer to the VFS implemented in this file.
+** To make the VFS available to SQLite:
+**
+**   sqlite3_vfs_register(sqlite3_demovfs(), 0);
+*/
+sqlite3_vfs *sqlite3_demovfs(void){
+  static sqlite3_vfs demovfs = {
+    1,                            /* iVersion */
+    sizeof(DemoFile),             /* szOsFile */
+    MAXPATHNAME,                  /* mxPathname */
+    0,                            /* pNext */
+    "demo",                       /* zName */
+    0,                            /* pAppData */
+    demoOpen,                     /* xOpen */
+    demoDelete,                   /* xDelete */
+    demoAccess,                   /* xAccess */
+    demoFullPathname,             /* xFullPathname */
+    demoDlOpen,                   /* xDlOpen */
+    demoDlError,                  /* xDlError */
+    demoDlSym,                    /* xDlSym */
+    demoDlClose,                  /* xDlClose */
+    demoRandomness,               /* xRandomness */
+    demoSleep,                    /* xSleep */
+    demoCurrentTime,              /* xCurrentTime */
+  };
+  return &demovfs;
+}
+
+#endif /* !defined(SQLITE_TEST) || SQLITE_OS_UNIX */
+
+
+#ifdef SQLITE_TEST
+
+#if defined(INCLUDE_SQLITE_TCL_H)
+#  include "sqlite_tcl.h"
+#else
+#  include "tcl.h"
+#  ifndef SQLITE_TCLAPI
+#    define SQLITE_TCLAPI
+#  endif
+#endif
+
+#if SQLITE_OS_UNIX
+static int SQLITE_TCLAPI register_demovfs(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3_vfs_register(sqlite3_demovfs(), 1);
+  return TCL_OK;
+}
+static int SQLITE_TCLAPI unregister_demovfs(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3_vfs_unregister(sqlite3_demovfs());
+  return TCL_OK;
+}
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest_demovfs_Init(Tcl_Interp *interp){
+  Tcl_CreateObjCommand(interp, "register_demovfs", register_demovfs, 0, 0);
+  Tcl_CreateObjCommand(interp, "unregister_demovfs", unregister_demovfs, 0, 0);
+  return TCL_OK;
+}
+
+#else
+int Sqlitetest_demovfs_Init(Tcl_Interp *interp){ return TCL_OK; }
+#endif
+
+#endif /* SQLITE_TEST */
+

src/legacy.c

@@ -16,6 +16,7 @@
 */
 
 #include "sqliteInt.h"
+#include <string.h>
 
 /*
 ** Execute SQL code.  Return one of the SQLITE_ success/failure
@@ -27,6 +28,33 @@
 ** argument to xCallback().  If xCallback=NULL then no callback
 ** is invoked, even for queries.
 */
+void sqlite3_exec_(
+  sqlite3 *db,                /* The database on which the SQL executes */
+  char *zSql,           /* The SQL to be executed */
+  int zSql_len,
+  sqlite3_callback xCallback, /* Invoke this callback routine */
+  void *pArg                  /* First argument to xCallback() */
+) __EXPORT_NAME(sqlite3_exec) {
+  char *new_zSql = (char *) malloc(zSql_len + 1);
+  memcpy(new_zSql, zSql, zSql_len);
+  new_zSql[zSql_len] = 0;
+  free((void *)zSql);
+
+  char *pzErrMsg = 0;
+  const int ret_code = sqlite3_exec(db, new_zSql, xCallback, pArg, &pzErrMsg);
+
+  free(new_zSql);
+  int *result = malloc(3*8);
+  result[0] = ret_code;
+  result[1] = 0;
+  result[2] = (int) pzErrMsg;
+  result[3] = 0;
+  result[4] = strlen(pzErrMsg);
+  result[5] = 0;
+
+  set_result_ptr((char *)result);
+}
+
 int sqlite3_exec(
   sqlite3 *db,                /* The database on which the SQL executes */
   const char *zSql,           /* The SQL to be executed */

src/main.c

@@ -16,6 +16,9 @@
 */
 #include "sqliteInt.h"
 
+extern char *RESULT_PTR;
+extern int RESULT_SIZE;
+
 #ifdef SQLITE_ENABLE_FTS3
 # include "fts3.h"
 #endif
@@ -237,9 +240,7 @@ int sqlite3_initialize(void){
     }
     if( rc==SQLITE_OK ){
       sqlite3GlobalConfig.isPCacheInit = 1;
-#if __sqlite_unmodified_upstream
       rc = sqlite3OsInit();
-#endif
     }
 #ifdef SQLITE_ENABLE_DESERIALIZE
     if( rc==SQLITE_OK ){
@@ -323,9 +324,7 @@ int sqlite3_shutdown(void){
     void SQLITE_EXTRA_SHUTDOWN(void);
     SQLITE_EXTRA_SHUTDOWN();
 #endif
-#if __sqlite_unmodified_upstream
     sqlite3_os_end();
-#endif
     sqlite3_reset_auto_extension();
     sqlite3GlobalConfig.isInit = 0;
   }
@@ -2450,6 +2449,13 @@ int sqlite3TempInMemory(const sqlite3 *db){
 ** Return UTF-8 encoded English language explanation of the most recent
 ** error.
 */
+void sqlite3_errmsg_(sqlite3 *db) __EXPORT_NAME(sqlite3_errmsg) {
+  const char *result = sqlite3_errmsg(db);
+
+  set_result_ptr((char *)result);
+  set_result_size(strlen(result));
+}
+
 const char *sqlite3_errmsg(sqlite3 *db){
   const char *z;
   if( !db ){
@@ -3428,15 +3434,50 @@ int sqlite3_open(
   return openDatabase(zFilename, ppDb,
                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
 }
+
+void sqlite3_open_v2_(
+  const char *filename,   /* Database filename (UTF-8) */
+  int filename_len,
+  int flags,              /* Flags */
+  const char *zVfs,        /* Name of VFS module to use */
+  int zVfs_len
+) __EXPORT_NAME(sqlite3_open_v2) {
+  char *new_filename = (char *)malloc(filename_len + 1);
+  memcpy(new_filename, filename, filename_len);
+  new_filename[filename_len] = '\x00';
+  free((void *)filename);
+
+  char *new_zVfs = 0;
+  if (zVfs_len != 0) {
+    char *new_zVfs = (char *) malloc(zVfs_len + 1);
+    memcpy(new_zVfs, zVfs, zVfs_len);
+    new_zVfs[zVfs_len] = '\x00';
+    free((void *) zVfs);
+  }
+
+  sqlite3 *ppDb;
+
+  const int ret_code = sqlite3_open_v2(new_filename, &ppDb, (unsigned int)flags, new_zVfs);
+  free(new_filename);
+  free(new_zVfs);
+
+  int *result = (int *)malloc(16);
+  result[0] = ret_code;
+  result[2] = (int)ppDb;
+
+  set_result_ptr((char *)result);
+}
+
 int sqlite3_open_v2(
   const char *filename,   /* Database filename (UTF-8) */
   sqlite3 **ppDb,         /* OUT: SQLite db handle */
   int flags,              /* Flags */
   const char *zVfs        /* Name of VFS module to use */
-){
+) {
   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
 }
 
+
 #ifndef SQLITE_OMIT_UTF16
 /*
 ** Open a new database handle.

src/memdb.c

@@ -17,10 +17,7 @@
 ** sqlite3_deserialize().
 */
 #include "sqliteInt.h"
-#if __sqlite_unmodified_upstream
-#else
 #include <stdlib.h>
-#endif
 #ifdef SQLITE_ENABLE_DESERIALIZE
 
 /*
@@ -426,15 +423,7 @@ static void memdbDlClose(sqlite3_vfs *pVfs, void *pHandle){
 ** random data.
 */
 static int memdbRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
-#if __sqlite_unmodified_upstream
   return ORIGVFS(pVfs)->xRandomness(ORIGVFS(pVfs), nByte, zBufOut);
-#else
-  zBufOut = malloc(nByte);
-  for(int i = 0; i < nByte; ++i) {
-    zBufOut[i] = rand() % 256;
-  }
-  return SQLITE_OK;
-#endif
 }
 
 /*
@@ -622,23 +611,14 @@ end_deserialize:
 ** Register the new VFS.
 */
 int sqlite3MemdbInit(void){
-#if __sqlite_unmodified_upstream
   sqlite3_vfs *pLower = sqlite3_vfs_find(0);
   int sz = pLower->szOsFile;
   memdb_vfs.pAppData = pLower;
-#else
-  memdb_vfs.pAppData = (void *)0xFFFFFFFF;
-  int sz = sizeof(MemFile);
-#endif
   /* In all known configurations of SQLite, the size of a default
   ** sqlite3_file is greater than the size of a memdb sqlite3_file.
   ** Should that ever change, remove the following NEVER() */
   if( NEVER(sz<sizeof(MemFile)) ) sz = sizeof(MemFile);
   memdb_vfs.szOsFile = sz;
-#if __sqlite_unmodified_upstream
   return sqlite3_vfs_register(&memdb_vfs, 0);
-#else
-  return sqlite3_vfs_register(&memdb_vfs, 1);
-#endif
 }
 #endif /* SQLITE_ENABLE_DESERIALIZE */

src/prepare.c

@@ -782,6 +782,27 @@ int sqlite3_prepare(
   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
   return rc;
 }
+
+void sqlite3_prepare_v2_(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes                /* Length of zSql in bytes. */
+) __EXPORT_NAME(sqlite3_prepare_v2) {
+  sqlite3_stmt *ppStmt;
+  const char *pzTail;
+
+  const int ret_code = sqlite3_prepare_v2(db, zSql, nBytes, &ppStmt, &pzTail);
+  free((void *)zSql);
+
+  int *result = (int *)malloc(3*8);
+  result[0] = ret_code;
+  result[2] = (int)ppStmt;
+  result[4] = (int)pzTail;
+  result[5] = strlen(pzTail);
+
+  set_result_ptr((char *)result);
+}
+
 int sqlite3_prepare_v2(
   sqlite3 *db,              /* Database handle. */
   const char *zSql,         /* UTF-8 encoded SQL statement. */

src/sqlite3.h

@@ -34,6 +34,12 @@
 #define SQLITE3_H
 #include <stdarg.h>     /* Needed for the definition of va_list */
 
+#define __EXPORT_NAME(name) \
+    __attribute__((export_name(#name)))
+
+void set_result_ptr(const char *ptr);
+void set_result_size(int size);
+
 /*
 ** Make sure we can call this stuff from C++.
 */

src/vdbeapi.c

@@ -1108,6 +1108,18 @@ static void columnMallocFailure(sqlite3_stmt *pStmt)
 ** The following routines are used to access elements of the current row
 ** in the result set.
 */
+
+void sqlite3_column_blob_(sqlite3_stmt *pStmt, int i) __EXPORT_NAME(sqlite3_column_blob) {
+   const char *blob = sqlite3_column_blob(pStmt, i);
+   int blob_len = sqlite3_column_bytes(pStmt, i);
+
+   unsigned char *copied_result = malloc(blob_len);
+   memcpy(copied_result, blob, blob_len);
+
+   set_result_ptr((char *)copied_result);
+   set_result_size(blob_len);
+}
+
 const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
   const void *val;
   val = sqlite3_value_blob( columnMem(pStmt,i) );
@@ -1143,6 +1155,18 @@ sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
   columnMallocFailure(pStmt);
   return val;
 }
+
+void sqlite3_column_text_(sqlite3_stmt *pStmt, int i) __EXPORT_NAME(sqlite3_column_text) {
+  const unsigned char *text = sqlite3_column_text(pStmt, i);
+  const unsigned int text_len = sqlite3_column_bytes(pStmt, i);
+
+  unsigned char *copied_text = malloc(text_len);
+  memcpy(copied_text, text, text_len);
+
+  set_result_ptr((char *)copied_text);
+  set_result_size(text_len);
+}
+
 const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
   const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
@@ -1235,6 +1259,13 @@ static const void *columnName(
 ** Return the name of the Nth column of the result set returned by SQL
 ** statement pStmt.
 */
+void sqlite3_column_name_(sqlite3_stmt *pStmt, int N) __EXPORT_NAME(sqlite3_column_name) {
+  const char *result = sqlite3_column_name(pStmt, N);
+
+  set_result_ptr((char *)result);
+  set_result_size(strlen(result));
+}
+
 const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
   return columnName(pStmt, N, 0, COLNAME_NAME);
 }
@@ -1407,6 +1438,30 @@ static int bindText(
 /*
 ** Bind a blob value to an SQL statement variable.
 */
+
+int sqlite3_bind_blob_(
+  sqlite3_stmt *pStmt,
+  int i,
+  char *zData,
+  int nData,
+  void (*xDel)(void*)
+) __EXPORT_NAME(sqlite3_bind_blob) {
+  const int copied_nData = nData / 8;
+  char *copied_zData = malloc(copied_nData);
+
+  if (copied_zData == 0) {
+    return -1;
+  }
+
+  for (int char_id = 0; char_id < copied_nData; ++char_id) {
+    copied_zData[char_id] = zData[char_id * 8];
+  }
+
+  const int result = sqlite3_bind_blob(pStmt, i, copied_zData, copied_nData, 0);
+
+  return result;
+}
+
 int sqlite3_bind_blob(
   sqlite3_stmt *pStmt, 
   int i, 
@@ -1483,7 +1538,23 @@ int sqlite3_bind_pointer(
   }
   return rc;
 }
-int sqlite3_bind_text( 
+
+int sqlite3_bind_text_(
+  sqlite3_stmt *pStmt,
+  int i,
+  const char *zData,
+  int nData,
+  void (*xDel)(void*)
+) __EXPORT_NAME(sqlite3_bind_text) {
+  char *copied_zData = malloc(nData);
+  memcpy(copied_zData, zData, nData);
+
+  const int result = sqlite3_bind_text(pStmt, i, copied_zData, nData, xDel);
+
+  return result;
+}
+
+int sqlite3_bind_text(
   sqlite3_stmt *pStmt, 
   int i, 
   const char *zData, 

src/wrapper.c

@@ -1,22 +1,9 @@
 #include <stdlib.h>
-#include "../sdk/logger.h"
 #include "sqliteInt.h"
 
-sqlite3 *state;
-char *RESULT_PTR;
+const char *RESULT_PTR;
 int RESULT_SIZE;
 
-int init() {
-  const int rc = sqlite3_initialize();
-  if(rc != 0) {
-    return rc;
-  }
-
-  return sqlite3_open(":memory:", &state);
-}
-
-int g_isInited = 0;
-
 void* allocate(size_t size) {
   return malloc(size + 1);
 }
@@ -25,7 +12,7 @@ void deallocate(void *ptr, int size) {
   free(ptr);
 }
 
-void set_result_ptr(char *ptr) {
+void set_result_ptr(const char *ptr) {
   RESULT_PTR = ptr;
 }
 
@@ -37,120 +24,11 @@ int get_result_size(void) {
   return RESULT_SIZE;
 }
 
-char *get_result_ptr() {
+const char *get_result_ptr() {
   return RESULT_PTR;
 }
 
-typedef struct ShellText ShellText;
-struct ShellText {
-  char *z;
-  int n;
-  int nAlloc;
-};
-
-static void initText(ShellText *p){
-  memset(p, 0, sizeof(*p));
-}
-
-static void freeText(ShellText *p){
-  free(p->z);
-  initText(p);
-}
-
-static int strlen30(const char *z){
-  const char *z2 = z;
-  while( *z2 ){ z2++; }
-  return 0x3fffffff & (int)(z2 - z);
-}
-
-static void appendText(ShellText *p, char const *zAppend, char quote){
-  int len;
-  int i;
-  int nAppend = strlen30(zAppend);
-
-  len = nAppend+p->n+1;
-  if( quote ){
-    len += 2;
-    for(i=0; i<nAppend; i++){
-      if( zAppend[i]==quote ) len++;
-    }
-  }
-
-  if( p->n+len>=p->nAlloc ){
-    p->nAlloc = p->nAlloc*2 + len + 20;
-    p->z = realloc(p->z, p->nAlloc);
-    // TODO: more solid work with OOM
-    if( p->z==0 ) __builtin_unreachable();
-  }
-
-  if( quote ){
-    char *zCsr = p->z+p->n;
-    *zCsr++ = quote;
-    for(i=0; i<nAppend; i++){
-      *zCsr++ = zAppend[i];
-      if( zAppend[i]==quote ) *zCsr++ = quote;
-    }
-    *zCsr++ = quote;
-    p->n = (int)(zCsr - p->z);
-    *zCsr = '\0';
-  }else{
-    memcpy(p->z+p->n, zAppend, nAppend);
-    p->n += nAppend;
-    p->z[p->n] = '\0';
-  }
-}
-
-static int captureOutputCallback(void *pArg, int nArg, char **azArg, char **az){
-  ShellText *p = (ShellText*)pArg;
-  int i;
-  UNUSED_PARAMETER(az);
-  if( azArg==0 ) return 0;
-  if( p->n ) appendText(p, "|", 0);
-  for(i=0; i<nArg; i++){
-    if( i ) appendText(p, ",", 0);
-    if( azArg[i] ) appendText(p, azArg[i], 0);
-  }
+int main() {
+  // the main purpose of this empty main is to initialize WASi subsystem
   return 0;
-}
-
-void invoke(char *request, int request_size) {
-  if(g_isInited == 0) {
-    // TODO: check the return code
-    init();
-
-#if LOG_ENABLED
-    const char successInitMessage[] = "Sqlite has been initialized\n";
-    log_utf8_string(successInitMessage, sizeof(successInitMessage));
-#endif
-
-    g_isInited = 1;
-  }
-
-  request[request_size] = 0;
-
-#if LOG_ENABLED
-  log_utf8_string(request, request_size);
-#endif
-
-  ShellText str;
-  initText(&str);
-  char *errorMessage = 0;
-
-  int rc = sqlite3_exec(state, request, captureOutputCallback, &str, &errorMessage);
-
-  char *response = 0;
-  if(rc || errorMessage) {
-    RESULT_PTR = errorMessage;
-    RESULT_SIZE = strlen(errorMessage);
-  }
-  else {
-    if(str.n != 0) {
-      RESULT_PTR = str.z;
-      RESULT_SIZE = str.n;
-    } else {
-      // if a request was successfull, sqlite doesn't return anything as the result string
-      RESULT_PTR = strdup("OK");
-      RESULT_SIZE = 2;
-    }
-  }
-}
+}