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, 117 insertions, 0 deletions

diff --git a/vendor/modernc.org/libc/mem.go b/vendor/modernc.org/libc/mem.go
new file mode 100644
index 000000000..23c2ec060
--- /dev/null
+++ b/vendor/modernc.org/libc/mem.go
@@ -0,0 +1,117 @@
+// Copyright 2021 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.
+
+// +build !libc.membrk,!libc.memgrind
+
+package libc // import "modernc.org/libc"
+
+import (
+	"modernc.org/libc/errno"
+	"modernc.org/libc/sys/types"
+	"modernc.org/memory"
+)
+
+const memgrind = false
+
+var (
+	allocator memory.Allocator
+)
+
+// void *malloc(size_t size);
+func Xmalloc(t *TLS, n types.Size_t) uintptr {
+	if n == 0 {
+		return 0
+	}
+
+	allocMu.Lock()
+
+	defer allocMu.Unlock()
+
+	p, err := allocator.UintptrMalloc(int(n))
+	if err != nil {
+		t.setErrno(errno.ENOMEM)
+		return 0
+	}
+
+	return p
+}
+
+// void *calloc(size_t nmemb, size_t size);
+func Xcalloc(t *TLS, n, size types.Size_t) uintptr {
+	rq := int(n * size)
+	if rq == 0 {
+		return 0
+	}
+
+	allocMu.Lock()
+
+	defer allocMu.Unlock()
+
+	p, err := allocator.UintptrCalloc(int(n * size))
+	if err != nil {
+		t.setErrno(errno.ENOMEM)
+		return 0
+	}
+
+	return p
+}
+
+// void *realloc(void *ptr, size_t size);
+func Xrealloc(t *TLS, ptr uintptr, size types.Size_t) uintptr {
+	allocMu.Lock()
+
+	defer allocMu.Unlock()
+
+	p, err := allocator.UintptrRealloc(ptr, int(size))
+	if err != nil {
+		t.setErrno(errno.ENOMEM)
+		return 0
+	}
+
+	return p
+}
+
+// void free(void *ptr);
+func Xfree(t *TLS, p uintptr) {
+	if p == 0 {
+		return
+	}
+
+	allocMu.Lock()
+
+	defer allocMu.Unlock()
+
+	allocator.UintptrFree(p)
+}
+
+func UsableSize(p uintptr) types.Size_t {
+	allocMu.Lock()
+
+	defer allocMu.Unlock()
+
+	return types.Size_t(memory.UintptrUsableSize(p))
+}
+
+// MemAuditStart locks the memory allocator, initializes and enables memory
+// auditing. Finaly it unlocks the memory allocator.
+//
+// Some memory handling errors, like double free or freeing of unallocated
+// memory, will panic when memory auditing is enabled.
+//
+// This memory auditing functionality has to be enabled using the libc.memgrind
+// build tag.
+//
+// It is intended only for debug/test builds. It slows down memory allocation
+// routines and it has additional memory costs.
+func MemAuditStart() {}
+
+// MemAuditReport locks the memory allocator, reports memory leaks, if any.
+// Finally it disables memory auditing and unlocks the memory allocator.
+//
+// This memory auditing functionality has to be enabled using the libc.memgrind
+// build tag.
+//
+// It is intended only for debug/test builds. It slows down memory allocation
+// routines and it has additional memory costs.
+func MemAuditReport() error { return nil }