From b7bedc8b60ccfa4ca33bf5b1f7d870c24e8725ef Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@users.sourceforge.net>
Date: Tue, 26 Feb 2013 21:26:45 +0100
Subject: [PATCH] Reduces memory occupation with many files.

---
 elem.c |  9 ++++++++-
 elem.h |  7 ++++++-
 scan.c |  2 +-
 util.c | 22 ++++++++++++++++++++++
 util.h |  6 ++++++
 5 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/elem.c b/elem.c
index 291ea4ce..e3c00954 100644
--- a/elem.c
+++ b/elem.c
@@ -331,7 +331,7 @@ struct snapraid_file* file_alloc(unsigned block_size, const char* sub, uint64_t
 	block_off_t i;
 
 	file = malloc_nofail(sizeof(struct snapraid_file));
-	pathcpy(file->sub, sizeof(file->sub), sub);
+	file->sub = strdup_nofail(sub);
 	file->size = size;
 	file->blockmax = (size + block_size - 1) / block_size;
 	file->mtime_sec = mtime_sec;
@@ -352,10 +352,17 @@ struct snapraid_file* file_alloc(unsigned block_size, const char* sub, uint64_t
 
 void file_free(struct snapraid_file* file)
 {
+	free(file->sub);
 	free(file->blockvec);
 	free(file);
 }
 
+void file_rename(struct snapraid_file* file, const char* sub)
+{
+	free(file->sub);
+	file->sub = strdup_nofail(sub);
+}
+
 const char* file_name(struct snapraid_file* file)
 {
 	const char* r = strrchr(file->sub, '/');
diff --git a/elem.h b/elem.h
index d2f12e0c..6e73cae5 100644
--- a/elem.h
+++ b/elem.h
@@ -159,7 +159,7 @@ struct snapraid_file {
 	int mtime_nsec; /**< Modification time nanoseconds. In the range 0 <= x < 1,000,000,000, or FILE_MTIME_NSEC_INVALID. */
 	block_off_t blockmax; /**< Number of blocks. */
 	unsigned flag; /**< FILE_IS_* flags. */
-	char sub[PATH_MAX]; /**< Sub path of the file. Without the disk dir. The disk is implicit. */
+	char* sub; /**< Sub path of the file. Without the disk dir. The disk is implicit. */
 
 	/* nodes for data structures */
 	tommy_node nodelist;
@@ -464,6 +464,11 @@ struct snapraid_file* file_alloc(unsigned block_size, const char* sub, uint64_t
  */
 void file_free(struct snapraid_file* file);
 
+/**
+ * Rename a file.
+ */
+void file_rename(struct snapraid_file* file, const char* sub);
+
 /**
  * Returns the name of the file, without the dir.
  */
diff --git a/scan.c b/scan.c
index ceb4289c..816491c4 100644
--- a/scan.c
+++ b/scan.c
@@ -339,7 +339,7 @@ static void scan_file(struct snapraid_scan* scan, struct snapraid_state* state,
 				tommy_hashdyn_remove_existing(&disk->pathset, &file->pathset);
 
 				/* save the new name */
-				pathcpy(file->sub, sizeof(file->sub), sub);
+				file_rename(file, sub);
 
 				/* reinsert in the set */
 				tommy_hashdyn_insert(&disk->pathset, &file->pathset, file, file_path_hash(file->sub));
diff --git a/util.c b/util.c
index 38a085cc..8c608bf8 100644
--- a/util.c
+++ b/util.c
@@ -755,6 +755,28 @@ void* malloc_nofail_align(size_t size, void** freeptr)
 	return ptr;
 }
 
+char* strdup_nofail(const char* str)
+{
+	size_t size;
+	char* ptr;
+
+	size = strlen(str) + 1;
+
+	ptr = malloc(size);
+
+	if (!ptr) {
+		/* don't use printf to avoid any possible extra allocation */
+		write(2, "Low Memory\n", 11);
+		exit(EXIT_FAILURE);
+	}
+
+	memcpy(ptr, str, size);
+
+	mcounter += size;
+
+	return ptr;
+}
+
 #include "murmurhash3.c"
 
 void memhash(unsigned kind, void* digest, const void* src, unsigned size)
diff --git a/util.h b/util.h
index 987c967f..f2a26cb4 100644
--- a/util.h
+++ b/util.h
@@ -369,6 +369,12 @@ void* malloc_nofail(size_t size);
  */
 void* malloc_nofail_align(size_t size, void** freeptr);
 
+/**
+ * Safe strdup.
+ * If no memory is available, it aborts.
+ */
+char* strdup_nofail(const char* str);
+
 /****************************************************************************/
 /* hash */