1 files changed, 287 insertions, 0 deletions
diff --git a/ubi-utils/src/eb_chain.c b/ubi-utils/src/eb_chain.c
new file mode 100644
index 0000000..501a838
--- /dev/null
+++ b/ubi-utils/src/eb_chain.c
@@ -0,0 +1,287 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * Author:  Drake Dowsett, dowsett@de.ibm.com
+ * Contact: Andreas Arnez, arnez@de.ibm.com
+ */
+
+/* see eb_chain.h */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include "eb_chain.h"
+
+#define COPY(dst, src)							\
+	do								\
+	{								\
+		dst = malloc(sizeof(*dst));				\
+		if (dst == NULL)					\
+			return -ENOMEM;					\
+		memcpy(dst, src, sizeof(*dst));				\
+	} while (0)
+
+
+/**
+ * inserts an eb_info into the chain starting at head, then searching
+ * linearly for the correct position;
+ * new should contain valid vid and ec headers and the data_crc should
+ * already have been checked before insertion, otherwise the chain
+ * could be have un an undesired manner;
+ * returns -ENOMEM if alloc fails, otherwise SHOULD always return 0,
+ * if not, the code reached the last line and returned -EAGAIN,
+ * meaning there is a bug or a case not being handled here;
+ **/
+int
+eb_chain_insert(eb_info_t *head, eb_info_t new)
+{
+	uint32_t vol, num, ver;
+	uint32_t new_vol, new_num, new_ver;
+	eb_info_t prev, cur, hist, ins;
+	eb_info_t *prev_ptr;
+
+	if ((head == NULL) || (new == NULL))
+		return 0;
+
+	if (*head == NULL)
+	{
+		COPY(*head, new);
+		(*head)->next = NULL;
+		return 0;
+	}
+
+	new_vol = ubi32_to_cpu(new->inner.vol_id);
+	new_num = ubi32_to_cpu(new->inner.lnum);
+	new_ver = ubi32_to_cpu(new->inner.leb_ver);
+
+	/** TRAVERSE HORIZONTALY **/
+
+	cur = *head;
+	prev = NULL;
+
+	/* traverse until vol_id/lnum align */
+	vol = ubi32_to_cpu(cur->inner.vol_id);
+	num = ubi32_to_cpu(cur->inner.lnum);
+	while ((new_vol > vol) || ((new_vol == vol) && (new_num > num)))
+	{
+		/* insert new at end of chain */
+		if (cur->next == NULL)
+		{
+			COPY(ins, new);
+			ins->next = NULL;
+			cur->next = ins;
+			return 0;
+		}
+
+		prev = cur;
+		cur = cur->next;
+		vol = ubi32_to_cpu(cur->inner.vol_id);
+		num = ubi32_to_cpu(cur->inner.lnum);
+	}
+
+	if (prev == NULL)
+		prev_ptr = head;
+	else
+		prev_ptr = &(prev->next);
+
+	/* insert new into the middle of chain */
+	if ((new_vol != vol) || (new_num != num))
+	{
+		COPY(ins, new);
+		ins->next = cur;
+		*prev_ptr = ins;
+		return 0;
+	}
+
+	/** TRAVERSE VERTICALY **/
+
+	hist = cur;
+	prev = NULL;
+
+	/* traverse until versions align */
+	ver = ubi32_to_cpu(cur->inner.leb_ver);
+	while (new_ver < ver)
+	{
+		/* insert new at bottom of history */
+		if (hist->older == NULL)
+		{
+			COPY(ins, new);
+			ins->next = NULL;
+			ins->older = NULL;
+			hist->older = ins;
+			return 0;
+		}
+
+		prev = hist;
+		hist = hist->older;
+		ver = ubi32_to_cpu(hist->inner.leb_ver);
+	}
+
+	if (prev == NULL)
+	{
+		/* replace active version */
+		COPY(ins, new);
+		ins->next = hist->next;
+		*prev_ptr = ins;
+
+		/* place cur in vertical histroy */
+		ins->older = hist;
+		hist->next = NULL;
+		return 0;
+	}
+	else
+	{
+		/* insert between versions, beneath active version */
+		COPY(ins, new);
+		ins->next = NULL;
+		ins->older = prev->older;
+		prev->older = ins;
+		return 0;
+	}
+
+	/* logically impossible to reach this point... hopefully */
+	return -EAGAIN;
+}
+
+
+/**
+ * sets the pointer at pos to the position of the first entry in the chain
+ * with of vol_id and, if given, with the same lnum as *lnum;
+ * if there is no entry in the chain, then *pos is NULL on return;
+ * always returns 0;
+ **/
+int
+eb_chain_position(eb_info_t *head, uint32_t vol_id, uint32_t *lnum,
+		  eb_info_t *pos)
+{
+	uint32_t vol, num;
+	eb_info_t cur;
+
+	if ((head == NULL) || (*head == NULL) || (pos == NULL))
+		return 0;
+
+	*pos = NULL;
+
+	cur = *head;
+	while (cur != NULL)
+	{
+		vol = ubi32_to_cpu(cur->inner.vol_id);
+		num = ubi32_to_cpu(cur->inner.lnum);
+
+		if (vol_id == vol)
+			if ((lnum == NULL) || (*lnum == num))
+			{
+				*pos = cur;
+				return 0;
+			}
+
+		cur = cur->next;
+	}
+
+	return 0;
+}
+
+
+/**
+ * prints to stream, the vol_id, lnum and leb_ver for each entry in the
+ * chain, starting at head;
+ * this is intended for debuging purposes;
+ * always returns 0;
+ **/
+int
+eb_chain_print(FILE* stream, eb_info_t *head)
+{
+	eb_info_t cur;
+
+	if (head == NULL)
+		return 0;
+
+	if (stream == NULL)
+		stream = stdout;
+
+	if (*head == NULL)
+	{
+		fprintf(stream, "EMPTY\n");
+		return 0;
+	}
+
+	cur = *head;
+	while (cur != NULL)
+	{
+		eb_info_t hist;
+
+		fprintf(stream, "  VOL %4u-%04u | VER 0x%8x\n",
+			ubi32_to_cpu(cur->inner.vol_id),
+			ubi32_to_cpu(cur->inner.lnum),
+			ubi32_to_cpu(cur->inner.leb_ver));
+
+		hist = cur->older;
+		while (hist != NULL)
+		{
+			fprintf(stream, "+ VOL %4u-%04u | VER 0x%8x\n",
+				ubi32_to_cpu(hist->inner.vol_id),
+				ubi32_to_cpu(hist->inner.lnum),
+				ubi32_to_cpu(hist->inner.leb_ver));
+
+			hist = hist->older;
+		}
+
+		cur = cur->next;
+	}
+
+	return 0;
+}
+
+
+/**
+ * frees the memory of the entire chain, starting at head;
+ * head will be NULL on return;
+ * always returns 0;
+ **/
+int
+eb_chain_destroy(eb_info_t *head)
+{
+	if (head == NULL)
+		return 0;
+
+	while (*head != NULL)
+	{
+		eb_info_t cur;
+		eb_info_t hist;
+
+		cur = *head;
+		*head = (*head)->next;
+
+		hist = cur->older;
+		while (hist != NULL)
+		{
+			eb_info_t temp;
+
+			temp = hist;
+			hist = hist->older;
+
+			free(temp);
+		}
+
+		free(cur);
+	}
+
+	return 0;
+}
+