A src/util/patch-fast.c

@@ -0,0 +1,130 @@
+/* Copyright (c) 2013-2016 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "patch-fast.h"
+
+DEFINE_VECTOR(PatchFastExtents, struct PatchFastExtent);
+
+size_t _fastOutputSize(struct Patch* patch, size_t inSize);
+bool _fastApplyPatch(struct Patch* patch, const void* in, size_t inSize, void* out, size_t outSize);
+
+void initPatchFast(struct PatchFast* patch) {
+	PatchFastExtentsInit(&patch->extents, 32);
+	patch->d.outputSize = _fastOutputSize;
+	patch->d.applyPatch = _fastApplyPatch;
+}
+
+void deinitPatchFast(struct PatchFast* patch) {
+	PatchFastExtentsDeinit(&patch->extents);
+}
+
+bool diffPatchFast(struct PatchFast* patch, const void* restrict in, const void* restrict out, size_t size) {
+	PatchFastExtentsClear(&patch->extents);
+	const uint32_t* iptr = in;
+	const uint32_t* optr = out;
+	size_t extentOff = 0;
+	struct PatchFastExtent* extent = NULL;
+	size_t off;
+	for (off = 0; off < (size & ~15); off += 16) {
+		uint32_t a = iptr[0] ^ optr[0];
+		uint32_t b = iptr[1] ^ optr[1];
+		uint32_t c = iptr[2] ^ optr[2];
+		uint32_t d = iptr[3] ^ optr[3];
+		iptr += 4;
+		optr += 4;
+		if (a | b | c | d) {
+			if (!extent) {
+				extent = PatchFastExtentsAppend(&patch->extents);
+				extent->offset = off;
+				extentOff = 0;
+			}
+			extent->extent[extentOff] = a;
+			extent->extent[extentOff + 1] = b;
+			extent->extent[extentOff + 2] = c;
+			extent->extent[extentOff + 3] = d;
+			extentOff += 4;
+			if (extentOff == PATCH_FAST_EXTENT) {
+				extent->length = extentOff * 4;
+				extent = NULL;
+			}
+		} else if (extent) {
+			extent->length = extentOff * 4;
+			extent = NULL;
+		}
+	}
+	if (extent) {
+		extent->length = extentOff * 4;
+		extent = NULL;
+	}
+	const uint32_t* iptr8 = iptr;
+	const uint32_t* optr8 = optr;
+	for (; off < size; ++off) {
+		uint8_t a = iptr8[0] ^ optr8[0];
+		++iptr8;
+		++optr8;
+		if (a) {
+			if (!extent) {
+				extent = PatchFastExtentsAppend(&patch->extents);
+				extent->offset = off;
+			}
+			((uint8_t*) extent->extent)[extentOff] = a;
+			++extentOff;
+		} else if (extent) {
+			extent->length = extentOff;
+			extent = NULL;
+		}
+	}
+	if (extent) {
+		extent->length = extentOff;
+		extent = NULL;
+	}
+
+	return true;
+}
+
+size_t _fastOutputSize(struct Patch* patch, size_t inSize) {
+	UNUSED(patch);
+	return inSize;
+}
+
+bool _fastApplyPatch(struct Patch* p, const void* in, size_t inSize, void* out, size_t outSize) {
+	struct PatchFast* patch = (struct PatchFast*) p;
+	if (inSize != outSize) {
+		return false;
+	}
+	const uint32_t* iptr = in;
+	uint32_t* optr = out;
+	size_t lastWritten = 0;
+	size_t s;
+	for (s = 0; s < PatchFastExtentsSize(&patch->extents); ++s) {
+		struct PatchFastExtent* extent = PatchFastExtentsGetPointer(&patch->extents, s);
+		if (extent->length + extent->offset > outSize) {
+			return false;
+		}
+		memcpy(optr, iptr, extent->offset - lastWritten);
+		optr = (uint32_t*) out + extent->offset / 4;
+		iptr = (uint32_t*) in + extent->offset / 4;
+		uint32_t* eptr = extent->extent;
+		size_t off;
+		for (off = 0; off < (extent->length & ~15); off += 16) {
+			optr[0] = iptr[0] ^ eptr[0];
+			optr[1] = iptr[1] ^ eptr[1];
+			optr[2] = iptr[2] ^ eptr[2];
+			optr[3] = iptr[3] ^ eptr[3];
+			optr += 4;
+			iptr += 4;
+			eptr += 4;
+		}
+		for (; off < extent->length; ++off) {
+			*(uint8_t*) optr = *(uint8_t*) iptr ^ *(uint8_t*) eptr;
+			++optr;
+			++iptr;
+			++eptr;
+		}
+		lastWritten = extent->offset + off;
+	}
+	memcpy(optr, iptr, outSize - lastWritten);
+	return true;
+}

A src/util/patch-fast.h

@@ -0,0 +1,34 @@
+/* Copyright (c) 2013-2016 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef PATCH_FAST_H
+#define PATCH_FAST_H
+
+#include "util/common.h"
+
+#include "util/patch.h"
+#include "util/vector.h"
+
+#define PATCH_FAST_EXTENT 256
+
+struct PatchFastExtent {
+	size_t length;
+	size_t offset;
+	uint32_t extent[PATCH_FAST_EXTENT];
+};
+
+DECLARE_VECTOR(PatchFastExtents, struct PatchFastExtent);
+
+struct PatchFast {
+	struct Patch d;
+
+	struct PatchFastExtents extents;
+};
+
+void initPatchFast(struct PatchFast*);
+void deinitPatchFast(struct PatchFast*);
+bool diffPatchFast(struct PatchFast* patch, const void* restrict in, const void* restrict out, size_t size);
+
+#endif