From: Eric Biggers <ebiggers3@gmail.com>
Date: Mon, 18 Jan 2016 04:43:30 +0000 (-0600)
Subject: inode_table: make the inode table resizable
X-Git-Tag: v1.9.0~7
X-Git-Url: https://wimlib.net/git/?p=wimlib;a=commitdiff_plain;h=d04a25a537201b46832cac28725a45bf559dc318

inode_table: make the inode table resizable
---

diff --git a/include/wimlib/bitops.h b/include/wimlib/bitops.h
index 191e95a1..14c73593 100644
--- a/include/wimlib/bitops.h
+++ b/include/wimlib/bitops.h
@@ -89,4 +89,14 @@ ffsw(machine_word_t v)
 		return ffs64(v);
 }
 
+/* Round up to nearest power of 2  */
+
+static inline size_t
+roundup_pow_of_2(size_t n)
+{
+	if (n <= 1)
+		return 1;
+	return (size_t)1 << (1 + flsw(n - 1));
+}
+
 #endif /* _WIMLIB_BITOPS_H */
diff --git a/include/wimlib/inode_table.h b/include/wimlib/inode_table.h
index 9e8485a1..4d4fab5e 100644
--- a/include/wimlib/inode_table.h
+++ b/include/wimlib/inode_table.h
@@ -3,6 +3,7 @@
 
 #include "wimlib/list.h"
 #include "wimlib/types.h"
+#include "wimlib/util.h"
 
 struct wim_dentry;
 
@@ -13,11 +14,20 @@ struct wim_dentry;
  * cases the inodes are linked by i_hlist_node.  */
 struct wim_inode_table {
 	struct hlist_head *array;
+	size_t filled;
 	size_t capacity;
 	struct hlist_head extra_inodes;
 };
 
 
+/* Compute the index of the hash bucket to use for the given inode number and
+ * device number.  */
+static inline size_t
+hash_inode(const struct wim_inode_table *table, u64 ino, u64 devno)
+{
+	return (hash_u64(ino) + devno) & (table->capacity - 1);
+}
+
 extern int
 init_inode_table(struct wim_inode_table *table, size_t capacity);
 
@@ -26,6 +36,9 @@ inode_table_new_dentry(struct wim_inode_table *table, const tchar *name,
 		       u64 ino, u64 devno, bool noshare,
 		       struct wim_dentry **dentry_ret);
 
+extern void
+enlarge_inode_table(struct wim_inode_table *table);
+
 extern void
 inode_table_prepare_inode_list(struct wim_inode_table *table,
 			       struct hlist_head *head);
diff --git a/src/blob_table.c b/src/blob_table.c
index 5d464a97..54eca2c9 100644
--- a/src/blob_table.c
+++ b/src/blob_table.c
@@ -54,21 +54,13 @@ struct blob_table {
 	size_t mask; /* capacity - 1; capacity is a power of 2  */
 };
 
-static size_t
-next_power_of_2(size_t n)
-{
-	if (n <= 1)
-		return 1;
-	return (size_t)1 << (1 + flsw(n - 1));
-}
-
 struct blob_table *
 new_blob_table(size_t capacity)
 {
 	struct blob_table *table;
 	struct hlist_head *array;
 
-	capacity = next_power_of_2(capacity);
+	capacity = roundup_pow_of_2(capacity);
 
 	table = MALLOC(sizeof(struct blob_table));
 	if (table == NULL)
diff --git a/src/inode_fixup.c b/src/inode_fixup.c
index 51893fc1..b0b13aac 100644
--- a/src/inode_fixup.c
+++ b/src/inode_fixup.c
@@ -72,7 +72,7 @@ inode_table_insert(struct wim_dentry *dentry, void *_params)
 	}
 
 	/* Try adding this dentry to an existing inode.  */
-	pos = d_inode->i_ino % table->capacity;
+	pos = hash_inode(table, d_inode->i_ino, 0);
 	hlist_for_each_entry(inode, &table->array[pos], i_hlist_node) {
 		if (inode->i_ino != d_inode->i_ino) {
 			continue;
@@ -108,6 +108,8 @@ inode_table_insert(struct wim_dentry *dentry, void *_params)
 
 	/* Keep this dentry's inode.  */
 	hlist_add_head(&d_inode->i_hlist_node, &table->array[pos]);
+	if (++table->filled > table->capacity)
+		enlarge_inode_table(table);
 	return 0;
 }
 
@@ -175,7 +177,7 @@ dentry_tree_fix_inodes(struct wim_dentry *root, struct hlist_head *inode_list)
 
 	/* We use a hash table to map inode numbers to inodes.  */
 
-	ret = init_inode_table(&params.inode_table, 9001);
+	ret = init_inode_table(&params.inode_table, 64);
 	if (ret)
 		return ret;
 
diff --git a/src/inode_table.c b/src/inode_table.c
index e9c92d6a..248d0223 100644
--- a/src/inode_table.c
+++ b/src/inode_table.c
@@ -3,7 +3,7 @@
  */
 
 /*
- * Copyright (C) 2012, 2013, 2014 Eric Biggers
+ * Copyright (C) 2012-2016 Eric Biggers
  *
  * This file is free software; you can redistribute it and/or modify it under
  * the terms of the GNU Lesser General Public License as published by the Free
@@ -23,6 +23,7 @@
 #  include "config.h"
 #endif
 
+#include "wimlib/bitops.h"
 #include "wimlib/dentry.h"
 #include "wimlib/error.h"
 #include "wimlib/inode.h"
@@ -34,9 +35,11 @@
 int
 init_inode_table(struct wim_inode_table *table, size_t capacity)
 {
+	capacity = roundup_pow_of_2(capacity);
 	table->array = CALLOC(capacity, sizeof(table->array[0]));
 	if (!table->array)
 		return WIMLIB_ERR_NOMEM;
+	table->filled = 0;
 	table->capacity = capacity;
 	INIT_HLIST_HEAD(&table->extra_inodes);
 	return 0;
@@ -49,6 +52,32 @@ destroy_inode_table(struct wim_inode_table *table)
 	FREE(table->array);
 }
 
+/* Double the capacity of the inode hash table.  */
+void
+enlarge_inode_table(struct wim_inode_table *table)
+{
+	const size_t old_capacity = table->capacity;
+	const size_t new_capacity = old_capacity * 2;
+	struct hlist_head *old_array = table->array;
+	struct hlist_head *new_array;
+	struct wim_inode *inode;
+	struct hlist_node *tmp;
+
+	new_array = CALLOC(new_capacity, sizeof(struct hlist_head));
+	if (!new_array)
+		return;
+	table->array = new_array;
+	table->capacity = new_capacity;
+	for (size_t i = 0; i < old_capacity; i++) {
+		hlist_for_each_entry_safe(inode, tmp, &old_array[i], i_hlist_node) {
+			hlist_add_head(&inode->i_hlist_node,
+				       &new_array[hash_inode(table, inode->i_ino,
+							     inode->i_devno)]);
+		}
+	}
+	FREE(old_array);
+}
+
 /*
  * Allocate a new dentry, with hard link detection.
  *
@@ -98,8 +127,7 @@ inode_table_new_dentry(struct wim_inode_table *table, const tchar *name,
 		list = &table->extra_inodes;
 	} else {
 		/* Hard link detection  */
-		list = &table->array[hash_u64(hash_u64(ino) + hash_u64(devno))
-				     % table->capacity];
+		list = &table->array[hash_inode(table, ino, devno)];
 		hlist_for_each_entry(inode, list, i_hlist_node) {
 			if (inode->i_ino != ino || inode->i_devno != devno)
 				continue;
@@ -121,9 +149,12 @@ inode_table_new_dentry(struct wim_inode_table *table, const tchar *name,
 	if (ret)
 		return ret;
 	inode = dentry->d_inode;
-	hlist_add_head(&inode->i_hlist_node, list);
 	inode->i_ino = ino;
 	inode->i_devno = devno;
+	hlist_add_head(&inode->i_hlist_node, list);
+	if (list != &table->extra_inodes)
+		if (++table->filled > table->capacity)
+			enlarge_inode_table(table);
 	*dentry_ret = dentry;
 	return 0;
 }
diff --git a/src/update_image.c b/src/update_image.c
index c07b19d6..63982cfe 100644
--- a/src/update_image.c
+++ b/src/update_image.c
@@ -1095,7 +1095,7 @@ execute_update_commands(WIMStruct *wim,
 		inode_table = alloca(sizeof(struct wim_inode_table));
 		sd_set = alloca(sizeof(struct wim_sd_set));
 
-		ret = init_inode_table(inode_table, 9001);
+		ret = init_inode_table(inode_table, 64);
 		if (ret)
 			goto out;