Add SQLite support, fix un-thread-safe DB caches, small performance f… (#172)

* Add SQLite support, fix un-thread-safe DB caches, small performance fixes

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

* add SQLite licenses to README

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

* appease the linter, and fix my dumbass-ery

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

* make requested changes

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

* add back comment

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

1 files changed, 590 insertions, 0 deletions

diff --git a/vendor/modernc.org/libc/printf.go b/vendor/modernc.org/libc/printf.go
new file mode 100644
index 000000000..c755a5375
--- /dev/null
+++ b/vendor/modernc.org/libc/printf.go
@@ -0,0 +1,590 @@
+// Copyright 2020 The Libc Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package libc // import "modernc.org/libc"
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+	"strings"
+	"unsafe"
+)
+
+const (
+	modNone = iota
+	modHH
+	modH
+	modL
+	modLL
+	modQ
+	modCapitalL
+	modJ
+	modZ
+	modCapitalZ
+	modT
+	mod32
+	mod64
+)
+
+// Format of the format string
+//
+// The format string is a character string, beginning and ending in its initial
+// shift state, if any.  The format string is composed of zero or more
+// directives: ordinary  characters  (not  %), which  are  copied unchanged to
+// the output stream; and conversion specifications, each of which results in
+// fetching zero or more subsequent arguments.
+func printf(format, args uintptr) []byte {
+	buf := bytes.NewBuffer(nil)
+	for {
+		switch c := *(*byte)(unsafe.Pointer(format)); c {
+		case '%':
+			format = printfConversion(buf, format, &args)
+		case 0:
+			// if dmesgs {
+			// 	dmesg("%v: %q", origin(1), buf.Bytes())
+			// }
+			return buf.Bytes()
+		default:
+			format++
+			buf.WriteByte(c)
+		}
+	}
+}
+
+// Each conversion specification is introduced by the character %, and ends
+// with a conversion specifier.  In between there may be (in this order) zero
+// or more flags, an optional minimum field width, an optional  precision  and
+// an optional length modifier.
+func printfConversion(buf *bytes.Buffer, format uintptr, args *uintptr) uintptr {
+	format++ // '%'
+	spec := "%"
+
+	// Flags characters
+	//
+	// The character % is followed by zero or more of the following flags:
+flags:
+	for {
+		switch c := *(*byte)(unsafe.Pointer(format)); c {
+		case '#':
+			// The value should be converted to an "alternate form".  For o conversions,
+			// the first character of the output string is made zero (by prefixing a 0 if
+			// it was not zero already).  For x and  X  conversions,  a nonzero result has
+			// the string "0x" (or "0X" for X conversions) prepended to it.  For a, A, e,
+			// E, f, F, g, and G conversions, the result will always contain a decimal
+			// point, even if no digits follow it (normally, a decimal point appears in the
+			// results of those conversions only if a digit follows).  For g and G
+			// conversions, trailing  zeros are not removed from the result as they would
+			// otherwise be.  For other conversions, the result is undefined.
+			format++
+			spec += "#"
+		case '0':
+			// The  value  should  be zero padded.  For d, i, o, u, x, X, a, A, e, E, f, F,
+			// g, and G conversions, the converted value is padded on the left with zeros
+			// rather than blanks.  If the 0 and - flags both appear, the 0 flag is
+			// ignored.  If a precision is given with a numeric conversion (d, i, o, u, x,
+			// and X), the 0 flag is ignored.  For other conversions, the  behav‐ ior is
+			// undefined.
+			format++
+			spec += "0"
+		case '-':
+			// The  converted value is to be left adjusted on the field boundary.  (The
+			// default is right justification.)  The converted value is padded on the right
+			// with blanks, rather than on the left with blanks or zeros.  A - overrides a
+			// 0 if both are given.
+			format++
+			spec += "-"
+		case ' ':
+			// A blank should be left before a positive number (or empty string) produced
+			// by a signed conversion.
+			format++
+			spec += " "
+		case '+':
+			// A sign (+ or -) should always be placed before a number produced by a signed
+			// conversion.  By default, a sign is used only for negative numbers.  A +
+			// overrides a space  if  both  are used.
+			format++
+			spec += "+"
+		default:
+			break flags
+		}
+	}
+	format, width, hasWidth := parseFieldWidth(format)
+	if hasWidth {
+		spec += strconv.Itoa(width)
+	}
+	format, prec, hasPrecision := parsePrecision(format, args)
+	format, mod := parseLengthModifier(format)
+
+	var str string
+
+more:
+	// Conversion specifiers
+	//
+	// A character that specifies the type of conversion to be applied.  The
+	// conversion specifiers and their meanings are:
+	switch c := *(*byte)(unsafe.Pointer(format)); c {
+	case 'd', 'i':
+		// The  int argument is converted to signed decimal notation.  The precision,
+		// if any, gives the minimum number of digits that must appear; if the
+		// converted value requires fewer digits, it is padded on the left with zeros.
+		// The default precision is 1.  When 0 is printed with an explicit precision 0,
+		// the output is empty.
+		format++
+		var arg int64
+		switch mod {
+		case modNone, modL, modLL, mod64:
+			arg = VaInt64(args)
+		case modH:
+			arg = int64(int16(VaInt32(args)))
+		case modHH:
+			arg = int64(int8(VaInt32(args)))
+		case mod32:
+			arg = int64(VaInt32(args))
+		default:
+			panic(todo("", mod))
+		}
+
+		if arg == 0 && hasPrecision && prec == 0 {
+			break
+		}
+
+		if hasPrecision {
+			panic(todo("", prec))
+		}
+
+		f := spec + "d"
+		str = fmt.Sprintf(f, arg)
+	case 'u':
+		// The unsigned int argument is converted to unsigned decimal notation. The
+		// precision, if any, gives the minimum number of digits that must appear; if
+		// the converted value requires fewer digits, it is padded on the left with
+		// zeros.  The default precision is 1.  When 0 is printed with an explicit
+		// precision 0, the output is empty.
+		format++
+		var arg uint64
+		switch mod {
+		case modNone, modL, modLL, mod64:
+			arg = VaUint64(args)
+		case modH:
+			arg = uint64(uint16(VaInt32(args)))
+		case modHH:
+			arg = uint64(uint8(VaInt32(args)))
+		case mod32:
+			arg = uint64(VaInt32(args))
+		default:
+			panic(todo("", mod))
+		}
+
+		if arg == 0 && hasPrecision && prec == 0 {
+			break
+		}
+
+		if hasPrecision {
+			panic(todo("", prec))
+		}
+
+		f := spec + "d"
+		str = fmt.Sprintf(f, arg)
+	case 'o':
+		// The unsigned int argument is converted to unsigned octal notation. The
+		// precision, if any, gives the minimum number of digits that must appear; if
+		// the converted value requires fewer digits, it is padded on the left with
+		// zeros.  The default precision is 1.  When 0 is printed with an explicit
+		// precision 0, the output is empty.
+		format++
+		var arg uint64
+		switch mod {
+		case modNone, modL, modLL, mod64:
+			arg = VaUint64(args)
+		case modH:
+			arg = uint64(uint16(VaInt32(args)))
+		case modHH:
+			arg = uint64(uint8(VaInt32(args)))
+		case mod32:
+			arg = uint64(VaInt32(args))
+		default:
+			panic(todo("", mod))
+		}
+
+		if arg == 0 && hasPrecision && prec == 0 {
+			break
+		}
+
+		if hasPrecision {
+			panic(todo("", prec))
+		}
+
+		f := spec + "o"
+		str = fmt.Sprintf(f, arg)
+	case 'I':
+		if !isWindows {
+			panic(todo("%#U", c))
+		}
+
+		format++
+		switch c = *(*byte)(unsafe.Pointer(format)); c {
+		case 'x', 'X':
+			// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-wsprintfa
+			//
+			// Ix, IX
+			//
+			// 64-bit unsigned hexadecimal integer in lowercase or uppercase on 64-bit
+			// platforms, 32-bit unsigned hexadecimal integer in lowercase or uppercase on
+			// 32-bit platforms.
+			if unsafe.Sizeof(int(0)) == 4 {
+				mod = mod32
+			}
+		case '3':
+			// https://en.wikipedia.org/wiki/Printf_format_string#Length_field
+			//
+			// I32	For integer types, causes printf to expect a 32-bit (double word) integer argument.
+			format++
+			switch c = *(*byte)(unsafe.Pointer(format)); c {
+			case '2':
+				format++
+				mod = mod32
+				goto more
+			default:
+				panic(todo("%#U", c))
+			}
+		case '6':
+			// https://en.wikipedia.org/wiki/Printf_format_string#Length_field
+			//
+			// I64	For integer types, causes printf to expect a 64-bit (quad word) integer argument.
+			format++
+			switch c = *(*byte)(unsafe.Pointer(format)); c {
+			case '4':
+				format++
+				mod = mod64
+				goto more
+			default:
+				panic(todo("%#U", c))
+			}
+		default:
+			panic(todo("%#U", c))
+		}
+		fallthrough
+	case 'X':
+		fallthrough
+	case 'x':
+		// The unsigned int argument is converted to unsigned hexadecimal notation.
+		// The letters abcdef are used for x  conversions;  the letters ABCDEF are used
+		// for X conversions.  The precision, if any, gives the minimum number of
+		// digits that must appear; if the converted value requires fewer digits, it is
+		// padded on the left with zeros.  The default precision is 1.  When 0 is
+		// printed with an explicit precision 0, the output is empty.
+		format++
+		var arg uint64
+		switch mod {
+		case modNone, modL, modLL, mod64:
+			arg = VaUint64(args)
+		case modH:
+			arg = uint64(uint16(VaInt32(args)))
+		case modHH:
+			arg = uint64(uint8(VaInt32(args)))
+		case mod32:
+			arg = uint64(VaInt32(args))
+		default:
+			panic(todo("", mod))
+		}
+
+		if arg == 0 && hasPrecision && prec == 0 {
+			break
+		}
+
+		if strings.Contains(spec, "#") && arg == 0 {
+			spec = strings.ReplaceAll(spec, "#", "")
+		}
+		var f string
+		switch {
+		case hasPrecision:
+			f = fmt.Sprintf("%s.%d%c", spec, prec, c)
+		default:
+			f = spec + string(c)
+		}
+		str = fmt.Sprintf(f, arg)
+	case 'e', 'E':
+		// The double argument is rounded and converted in the style [-]d.ddde±dd where
+		// there is one digit before the decimal-point character and the number of
+		// digits after it is equal to  the precision;  if the precision is missing, it
+		// is taken as 6; if the precision is zero, no decimal-point character appears.
+		// An E conversion uses the letter E (rather than e) to intro‐ duce the
+		// exponent.  The exponent always contains at least two digits; if the value is
+		// zero, the exponent is 00.
+		format++
+		arg := VaFloat64(args)
+		if !hasPrecision {
+			prec = 6
+		}
+		f := fmt.Sprintf("%s.%d%c", spec, prec, c)
+		str = fmt.Sprintf(f, arg)
+	case 'f', 'F':
+		// The double argument is rounded and converted to decimal notation in the
+		// style [-]ddd.ddd, where the number of digits after the decimal-point
+		// character  is  equal  to  the  precision specification.   If  the  precision
+		// is missing, it is taken as 6; if the precision is explicitly zero, no
+		// decimal-point character appears.  If a decimal point appears, at least one
+		// digit appears before it.
+		format++
+		arg := VaFloat64(args)
+		if !hasPrecision {
+			prec = 6
+		}
+		f := fmt.Sprintf("%s.%d%c", spec, prec, c)
+		str = fmt.Sprintf(f, arg)
+	case 'G':
+		fallthrough
+	case 'g':
+		// The double argument is converted in style f or e (or F or E for G
+		// conversions).  The precision specifies the number of significant digits.  If
+		// the precision is missing, 6 digits are given;  if the precision is zero, it
+		// is treated as 1.  Style e is used if the exponent from its conversion is
+		// less than -4 or greater than or equal to the precision.  Trailing zeros are
+		// removed from the fractional part of the result; a decimal point appears only
+		// if it is followed by at least one digit.
+		format++
+		arg := VaFloat64(args)
+		if !hasPrecision {
+			prec = 6
+		}
+		if prec == 0 {
+			prec = 1
+		}
+
+		f := fmt.Sprintf("%s.%d%c", spec, prec, c)
+		str = fmt.Sprintf(f, arg)
+	case 's':
+		// If  no l modifier is present: the const char * argument is expected to be a
+		// pointer to an array of character type (pointer to a string).  Characters
+		// from the array are written up to (but not including) a terminating null byte
+		// ('\0'); if a precision is specified, no more than the number specified are
+		// written.  If a precision  is  given,  no  null  byte  need  be present; if
+		// the precision is not specified, or is greater than the size of the array,
+		// the array must contain a terminating null byte.
+		//
+		// If  an  l  modifier  is  present: the const wchar_t * argument is expected
+		// to be a pointer to an array of wide characters.  Wide characters from the
+		// array are converted to multibyte characters (each by a call to the
+		// wcrtomb(3) function, with a conversion state starting in the initial state
+		// before the first wide character), up to and including a terminating null
+		// wide  character.   The  resulting  multibyte  characters are written up to
+		// (but not including) the terminating null byte.  If a precision is specified,
+		// no more bytes than the number specified are written, but no partial
+		// multibyte characters are written.  Note that the precision determines the
+		// number of bytes written, not the number of wide characters or  screen
+		// positions.   The  array  must contain a terminating null wide character,
+		// unless a precision is given and it is so small that the number of bytes
+		// written exceeds it before the end of the array is reached.
+		format++
+		arg := VaUintptr(args)
+		switch mod {
+		case modNone:
+			var f string
+			switch {
+			case hasPrecision:
+				f = fmt.Sprintf("%s.%ds", spec, prec)
+				str = fmt.Sprintf(f, GoBytes(arg, prec))
+			default:
+				f = spec + "s"
+				str = fmt.Sprintf(f, GoString(arg))
+			}
+		default:
+			panic(todo(""))
+		}
+	case 'p':
+		// The void * pointer argument is printed in hexadecimal (as if by %#x or
+		// %#lx).
+		format++
+		arg := VaUintptr(args)
+		buf.WriteString("0x")
+		buf.WriteString(strconv.FormatInt(int64(arg), 16))
+	case 'c':
+		// If no l modifier is present, the int argument is converted to an unsigned
+		// char, and the resulting character is written.  If an l modifier is present,
+		// the wint_t (wide character) ar‐ gument is converted to a multibyte sequence
+		// by a call to the wcrtomb(3) function, with a conversion state starting in
+		// the initial state, and the resulting multibyte string is  writ‐ ten.
+		format++
+		switch mod {
+		case modNone:
+			arg := VaInt32(args)
+			buf.WriteByte(byte(arg))
+		default:
+			panic(todo(""))
+		}
+	case '%':
+		// A '%' is written.  No argument is converted.  The complete conversion
+		// specification is '%%'.
+		format++
+		buf.WriteByte('%')
+	default:
+		panic(todo("%#U", c))
+	}
+
+	buf.WriteString(str)
+	return format
+}
+
+// Field width
+//
+// An optional decimal digit string (with nonzero first digit) specifying a
+// minimum field width.  If the converted value has fewer characters than the
+// field width, it will be padded with spa‐ ces on the left (or right, if the
+// left-adjustment flag has been given).  Instead of a decimal digit string one
+// may write "*" or "*m$" (for some decimal integer m) to specify that the
+// field width  is  given  in the next argument, or in the m-th argument,
+// respectively, which must be of type int.  A negative field width is taken as
+// a '-' flag followed by a positive field width.  In no case does a
+// nonexistent or small field width cause truncation of a field; if the result
+// of a conversion is wider than the field width, the field is expanded to
+// contain the conversion result.
+func parseFieldWidth(format uintptr) (_ uintptr, n int, ok bool) {
+	first := true
+	for {
+		var digit int
+		switch c := *(*byte)(unsafe.Pointer(format)); {
+		case first && c == '0':
+			return format, n, ok
+		case first && c == '*':
+			panic(todo(""))
+		case c >= '0' && c <= '9':
+			format++
+			ok = true
+			first = false
+			digit = int(c) - '0'
+		default:
+			return format, n, ok
+		}
+
+		n0 := n
+		n = 10*n + digit
+		if n < n0 {
+			panic(todo(""))
+		}
+	}
+}
+
+// Precision
+//
+// An  optional precision, in the form of a period ('.')  followed by an
+// optional decimal digit string.  Instead of a decimal digit string one may
+// write "*" or "*m$" (for some decimal integer m) to specify that the
+// precision is given in the next argument, or in the m-th argument,
+// respectively, which must be of type int.  If the precision is given as just
+// '.', the  precision  is taken  to  be  zero.  A negative precision is taken
+// as if the precision were omitted.  This gives the minimum number of digits
+// to appear for d, i, o, u, x, and X conversions, the number of digits to
+// appear after the radix character for a, A, e, E, f, and F conversions, the
+// maximum number of significant digits for g and G conversions, or the maximum
+// number of characters to be printed from a string for s and S conversions.
+func parsePrecision(format uintptr, args *uintptr) (_ uintptr, n int, ok bool) {
+	for {
+		switch c := *(*byte)(unsafe.Pointer(format)); c {
+		case '.':
+			format++
+			first := true
+			for {
+				switch c := *(*byte)(unsafe.Pointer(format)); {
+				case first && c == '*':
+					format++
+					n = int(VaInt32(args))
+					return format, n, true
+				case c >= '0' && c <= '9':
+					format++
+					first = false
+					n0 := n
+					n = 10*n + (int(c) - '0')
+					if n < n0 {
+						panic(todo(""))
+					}
+				default:
+					return format, n, true
+				}
+			}
+		default:
+			return format, 0, false
+		}
+	}
+}
+
+// Length modifier
+//
+// Here, "integer conversion" stands for d, i, o, u, x, or X conversion.
+//
+// hh     A following integer conversion corresponds to a signed char or
+// unsigned char argument, or a following n conversion corresponds to a pointer
+// to a signed char argument.
+//
+// h      A following integer conversion corresponds to a short int or unsigned
+// short int argument, or a following n conversion corresponds to a pointer to
+// a short int argument.
+//
+// l      (ell)  A following integer conversion corresponds to a long int or
+// unsigned long int argument, or a following n conversion corresponds to a
+// pointer to a long int argument, or a fol‐ lowing c conversion corresponds to
+// a wint_t argument, or a following s conversion corresponds to a pointer to
+// wchar_t argument.
+//
+// ll     (ell-ell).  A following integer conversion corresponds to a long long
+// int or unsigned long long int argument, or a following n conversion
+// corresponds to a pointer to a long long int argument.
+//
+// q      A synonym for ll.  This is a nonstandard extension, derived from BSD;
+// avoid its use in new code.
+//
+// L      A following a, A, e, E, f, F, g, or G conversion corresponds to a
+// long double argument.  (C99 allows %LF, but SUSv2 does not.)
+//
+// j      A following integer conversion corresponds to an intmax_t or
+// uintmax_t argument, or a following n conversion corresponds to a pointer to
+// an intmax_t argument.
+//
+// z      A following integer conversion corresponds to a size_t or ssize_t
+// argument, or a following n conversion corresponds to a pointer to a size_t
+// argument.
+//
+// Z      A nonstandard synonym for z that predates the appearance of z.  Do
+// not use in new code.
+//
+// t      A following integer conversion corresponds to a ptrdiff_t argument,
+// or a following n conversion corresponds to a pointer to a ptrdiff_t
+// argument.
+
+func parseLengthModifier(format uintptr) (_ uintptr, n int) {
+	switch c := *(*byte)(unsafe.Pointer(format)); c {
+	case 'h':
+		format++
+		n = modH
+		switch c := *(*byte)(unsafe.Pointer(format)); c {
+		case 'h':
+			format++
+			n = modHH
+		}
+		return format, n
+	case 'l':
+		format++
+		n = modL
+		switch c := *(*byte)(unsafe.Pointer(format)); c {
+		case 'l':
+			format++
+			n = modLL
+		}
+		return format, n
+	case 'q':
+		panic(todo(""))
+	case 'L':
+		panic(todo(""))
+	case 'j':
+		panic(todo(""))
+	case 'z':
+		panic(todo(""))
+	case 'Z':
+		panic(todo(""))
+	case 't':
+		panic(todo(""))
+	default:
+		return format, 0
+	}
+}