pkg/midipak: add blockvfs patches/blockvfs

1 files changed, 107 insertions, 0 deletions

diff --git a/pkg/midipak/vfs/blockvfs.zig b/pkg/midipak/vfs/blockvfs.zig
new file mode 100644
index 0000000..0ab89eb
--- /dev/null
+++ b/pkg/midipak/vfs/blockvfs.zig
@@ -0,0 +1,107 @@
+const std = @import("std");
+
+const c = @cImport(@cInclude("sqlite3ext.h"));
+pub export var sqlite3_api: [*c]const c.sqlite3_api_routines = null;
+
+const maxPathSize = 256;
+const blocksize = 512;
+const blobsize = 1474560;
+
+const BlockFile = struct {
+    base: c.sqlite3_file
+};
+
+fn xOpen(vfs: [*c]c.sqlite3_vfs, zName: [*c]const u8, f: [*c]c.sqlite3_file, flags: c_int, pOutFlags: [*c]c_int) callconv(.C) c_int {
+    std.debug.print("xOpen: zName={s} flags={d}\n", .{ zName, flags });
+    return c.SQLITE_ERROR;
+}
+
+fn xDelete(vfs: [*c]c.sqlite3_vfs, zName: [*c]const u8, syncDir: c_int) callconv(.C) c_int {
+    return c.SQLITE_ERROR;
+}
+
+fn xAccess(vfs: [*c]c.sqlite3_vfs, zName: [*c]const u8, flags: c_int, pResOut: [*c]c_int) callconv(.C) c_int {
+    return c.SQLITE_ERROR;
+}
+
+fn xFullPathname(vfs: [*c]c.sqlite3_vfs, zName: [*c]const u8, nOut: c_int, zOut: [*c]u8) callconv(.C) c_int {
+    std.debug.print("xFullPathname: zName={s} nOut={d}\n", .{ zName, nOut });
+    const out = zOut[0..@intCast(usize, nOut)];
+    const name = std.mem.spanZ(zName);
+
+    if (name.len + 1 > maxPathSize) {
+        return c.SQLITE_CANTOPEN;
+    }
+
+    out[0] = '/';
+
+    std.mem.copy(u8, out[1..out.len], name);
+    return c.SQLITE_OK;
+}
+
+fn xDlOpen(vfs: [*c]c.sqlite3_vfs, zFilename: [*c]const u8) callconv(.C) ?*c_void {
+    return null;
+}
+fn xDlError(vfs: [*c]c.sqlite3_vfs, nByte: c_int, zErrMsg: [*c]u8) callconv(.C) void {}
+fn xDlSym(vfs: [*c]c.sqlite3_vfs, pHandle: ?*c_void, zSymbol: [*c]const u8) callconv(.C) ?fn () callconv(.C) void {
+    return xDlSym_;
+}
+fn xDlSym_() callconv(.C) void {}
+fn xDlClose(vfs: [*c]c.sqlite3_vfs, pHandle: ?*c_void) callconv(.C) void {}
+
+fn xRandomness(vfs: [*c]c.sqlite3_vfs, nByte: c_int, zOut: [*c]u8) callconv(.C) c_int {
+    return c.SQLITE_ERROR;
+}
+
+fn xSleep(vfs: [*c]c.sqlite3_vfs, microseconds: c_int) callconv(.C) c_int {
+    return c.SQLITE_ERROR;
+}
+
+fn xCurrentTime(vfs: [*c]c.sqlite3_vfs, prNow: [*c]f64) callconv(.C) c_int {
+    return c.SQLITE_ERROR;
+}
+
+fn xGetLastError(vfs: [*c]c.sqlite3_vfs, nBuf: c_int, zBuf: [*c]u8) callconv(.C) c_int {
+    return c.SQLITE_ERROR;
+}
+
+var blockvfs = c.sqlite3_vfs{
+    .iVersion = 1,
+    .szOsFile = @sizeOf(BlockFile),
+    .mxPathname = maxPathSize,
+    .pNext = null,
+    .zName = "blockvfs",
+    .pAppData = null,
+    .xOpen = xOpen,
+    .xDelete = xDelete,
+    .xAccess = xAccess,
+    .xFullPathname = xFullPathname,
+    .xDlOpen = xDlOpen,
+    .xDlError = xDlError,
+    .xDlSym = xDlSym,
+    .xDlClose = xDlClose,
+    .xRandomness = xRandomness,
+    .xSleep = xSleep,
+    .xCurrentTime = xCurrentTime,
+    .xGetLastError = xGetLastError,
+    .xCurrentTimeInt64 = null,
+    .xGetSystemCall = null,
+    .xSetSystemCall = null,
+    .xNextSystemCall = null,
+};
+
+pub export fn blockvfs_register() c_int {
+    std.debug.print("hello {s}!\n", .{blockvfs.zName});
+
+    return sqlite3_api.*.vfs_register.?(&blockvfs, 0);
+}
+
+pub export fn sqlite3_blockvfs_init(db: ?*c.sqlite3, pzErrMsg: [*c][*c]u8, pApi: [*c]const c.sqlite3_api_routines) c_int {
+    sqlite3_api = pApi;
+
+    const ret = blockvfs_register();
+    return switch (ret) {
+        c.SQLITE_OK => c.SQLITE_OK_LOAD_PERMANENTLY,
+        else => ret,
+    };
+}