diff mbox series

[V2,30/36] Introduce own version of zckRange from zchunk

Message ID 20211114172733.71602-31-sbabic@denx.de
State Changes Requested
Headers show
Series DELTA Update | expand

Commit Message

Stefano Babic Nov. 14, 2021, 5:27 p.m. UTC
Import from zchunk project code to generate a Bytes Request from a list
of chunks. Code is imported to get more control and internals to the
range as the original library.

Signed-off-by: Stefano Babic <sbabic@denx.de>
---
 handlers/zchunk_range.c | 187 ++++++++++++++++++++++++++++++++++++++++
 handlers/zchunk_range.h |  41 +++++++++
 2 files changed, 228 insertions(+)
 create mode 100644 handlers/zchunk_range.c
 create mode 100644 handlers/zchunk_range.h
diff mbox series

Patch

diff --git a/handlers/zchunk_range.c b/handlers/zchunk_range.c
new file mode 100644
index 0000000..5bdd5cd
--- /dev/null
+++ b/handlers/zchunk_range.c
@@ -0,0 +1,187 @@ 
+/*
+ * (C) Copyright 2021
+ * Stefano Babic, sbabic@denx.de.
+ * Copyright 2018 Jonathan Dieter <jdieter@gmail.com>
+ *
+ * SPDX-License-Identifier:	 GPL-2.0-only
+ */
+
+/*
+ * This code is mostly taken from "range.c" from the zchunk project.
+ * See Copyright above. Changes here are to get more internals from Range,
+ * that are not exported by zck library.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <math.h>
+#include <errno.h>
+#include <zck.h>
+#include "zchunk_range.h"
+#include "util.h"
+
+#define BUF_SIZE 32768
+static zck_range_item *range_insert_new(zck_range_item *prev,
+				        zck_range_item *next, uint64_t start,
+					uint64_t end) {
+	zck_range_item *new = calloc(1, sizeof(zck_range_item));
+	if (!new) {
+		ERROR("OOM in %s", __func__);
+		return NULL;
+	}
+	new->start = start;
+	new->end = end;
+	if(prev) {
+		new->prev = prev;
+		prev->next = new;
+	}
+	if(next) {
+		new->next = next;
+		next->prev = new;
+	}
+	return new;
+}
+
+static zck_range_item *range_remove(zck_range_item *range) {
+	zck_range_item *next = range->next;
+	if(range->next)
+		range->next->prev = range->prev;
+	free(range);
+	return next;
+}
+
+static void range_merge_combined(zck_range *info) {
+	if(!info) {
+		ERROR("zck_range not allocated");
+		return;
+	}
+	for(zck_range_item *ptr=info->first; ptr;) {
+		if(ptr->next && ptr->end >= ptr->next->start-1) {
+			if(ptr->end < ptr->next->end)
+				ptr->end = ptr->next->end;
+			ptr->next = range_remove(ptr->next);
+			info->count -= 1;
+		} else {
+			ptr = ptr->next;
+		}
+	}
+}
+
+static bool range_add(zck_range *info, zckChunk *chk) {
+	if(info == NULL || chk == NULL) {
+		ERROR("zck_range or zckChunk not allocated");
+		return false;
+	}
+
+	size_t start = zck_get_chunk_start(chk);
+	size_t end = zck_get_chunk_start(chk) + zck_get_chunk_comp_size(chk) - 1;
+	zck_range_item *prev = info->first;
+	for(zck_range_item *ptr=info->first; ptr;) {
+		prev = ptr;
+		if(start > ptr->start) {
+			ptr = ptr->next;
+			continue;
+		} else if(start < ptr->start) {
+			if(range_insert_new(ptr->prev, ptr, start, end) == NULL)
+				return false;
+			if(info->first == ptr) {
+				info->first = ptr->prev;
+			}
+			info->count += 1;
+			range_merge_combined(info);
+			return true;
+		} else { // start == ptr->start
+			if(end > ptr->end)
+				ptr->end = end;
+			info->count += 1;
+			range_merge_combined(info);
+			return true;
+		}
+	}
+	/* We've only reached here if we should be last item */
+	zck_range_item *new = range_insert_new(prev, NULL, start, end);
+	if(new == NULL)
+		return false;
+	if(info->first == NULL)
+		info->first = new;
+	info->count += 1;
+	range_merge_combined(info);
+	return true;
+}
+
+void zchunk_range_free(zck_range **info) {
+	zck_range_item *next = (*info)->first;
+	while(next) {
+		zck_range_item *tmp = next;
+		next = next->next;
+		free(tmp);
+	}
+	free(*info);
+	*info = NULL;
+}
+
+char *zchunk_get_range_char(zck_range *range) {
+	int buf_size = BUF_SIZE;
+	char *output = calloc(1, buf_size);
+	if (!output) {
+	   ERROR ("OOM in %s", __func__);
+	   return NULL;
+	}
+	int loc = 0;
+	int count = 0;
+	zck_range_item *ri = range->first;
+	while(ri) {
+		int length = snprintf(output+loc, buf_size-loc, "%lu-%lu,",
+				      (long unsigned)ri->start,
+				      (long unsigned)ri->end);
+		if(length < 0) {
+			ERROR("Unable to get range: %s", strerror(errno));
+			free(output);
+			return NULL;
+		}
+		if(length > buf_size-loc) {
+			buf_size = (int)(buf_size * 1.5);
+			output = saferealloc(output, buf_size);
+			if (!output) {
+				ERROR ("OOM in %s", __func__);
+				return output;
+			}
+			continue;
+		}
+		loc += length;
+		count++;
+		ri = ri->next;
+	}
+	output[loc-1]='\0'; // Remove final comma
+	output = saferealloc(output, loc);
+	return output;
+}
+
+zck_range *zchunk_get_missing_range(zckCtx *zck, zckChunk *first, int max_ranges) {
+	if (!zck)
+		return NULL;
+	zck_range *range = calloc(1, sizeof(zck_range));
+	if (!range) {
+		ERROR ("OOM in %s", __func__);
+		return NULL;
+	}
+
+	for(zckChunk *chk = first ? first : zck_get_first_chunk(zck); chk; chk = zck_get_next_chunk(chk)) {
+		if (zck_get_chunk_valid(chk))
+			continue;
+		if(!range_add(range, chk)) {
+			zchunk_range_free(&range);
+			return NULL;
+		}
+		if(max_ranges >= 0 && range->count >= max_ranges)
+			break;
+	}
+	return range;
+}
+
+int zchunk_get_range_count(zck_range *range) {
+	return range->count;
+}
diff --git a/handlers/zchunk_range.h b/handlers/zchunk_range.h
new file mode 100644
index 0000000..0a770fe
--- /dev/null
+++ b/handlers/zchunk_range.h
@@ -0,0 +1,41 @@ 
+/*
+ * (C) Copyright 2021
+ * Stefano Babic, sbabic@denx.de.
+ *
+ * SPDX-License-Identifier:     GPL-2.0-only
+ */
+
+#pragma once
+
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <zck.h>
+
+/* Contains a single range */
+typedef struct zck_range_item {
+    size_t start;
+    size_t end;
+    struct zck_range_item *next;
+    struct zck_range_item *prev;
+} zck_range_item;
+
+typedef struct zck_range {
+    unsigned int count;
+    zck_range_item *first;
+} zck_range;
+
+/* exported function */
+
+/* Get a Range from a zck context */
+zck_range *zchunk_get_missing_range(zckCtx *zck, zckChunk *chk, int max_ranges);
+
+/* Return number of ranges */
+int zchunk_get_range_count(zck_range *range);
+
+/* Return string to be used in HTTP Bytes Range */
+char *zchunk_get_range_char(zck_range *range);
+
+/* Free range allocated by zchunk_get_missing_range */
+void zchunk_range_free(zck_range **info);