From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Mon, 16 Nov 2020 15:57:39 +0000 (+0200)
Subject: lib: data-stack - Rename block_space_used[] to block_space_left[]
X-Git-Tag: 2.3.16~259
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8a37fc6f68f2a04d6cc4583b0b85d48e33d109db;p=thirdparty%2Fdovecot%2Fcore.git

lib: data-stack - Rename block_space_used[] to block_space_left[]

This describes its behavior better. Also add a comment explaining what
exactly it is.
---

diff --git a/src/lib/data-stack.c b/src/lib/data-stack.c
index 14e4022317..1c8ed4e3a7 100644
--- a/src/lib/data-stack.c
+++ b/src/lib/data-stack.c
@@ -50,7 +50,10 @@ struct stack_frame_block {
 	struct stack_frame_block *prev;
 
 	struct stack_block *block[BLOCK_FRAME_COUNT];
-	size_t block_space_used[BLOCK_FRAME_COUNT];
+	/* Each frame initializes this to current_block->left, i.e. how much
+	   free space is left in the block. So the frame's start position in
+	   the block is (block.size - block_space_left) */
+	size_t block_space_left[BLOCK_FRAME_COUNT];
 	size_t last_alloc_size[BLOCK_FRAME_COUNT];
 	const char *marker[BLOCK_FRAME_COUNT];
 #ifdef DEBUG
@@ -167,7 +170,7 @@ data_stack_frame_t t_push(const char *marker)
 
 	/* mark our current position */
 	current_frame_block->block[frame_pos] = current_block;
-	current_frame_block->block_space_used[frame_pos] = current_block->left;
+	current_frame_block->block_space_left[frame_pos] = current_block->left;
 	current_frame_block->last_alloc_size[frame_pos] = 0;
 	current_frame_block->marker[frame_pos] = marker;
 #ifdef DEBUG
@@ -244,7 +247,7 @@ static void t_pop_verify(void)
 	size_t pos, max_pos, used_size;
 
 	block = current_frame_block->block[frame_pos];
-	pos = block->size - current_frame_block->block_space_used[frame_pos];
+	pos = block->size - current_frame_block->block_space_left[frame_pos];
 	while (block != NULL) {
 		block_canary_check(block);
 		used_size = block->size - block->left;
@@ -292,13 +295,13 @@ void t_pop_last_unsafe(void)
 		size_t pos, used_size;
 
 		pos = current_block->size -
-			current_frame_block->block_space_used[frame_pos];
+			current_frame_block->block_space_left[frame_pos];
 		used_size = current_block->size - current_block->lowwater;
 		i_assert(used_size >= pos);
 		memset(STACK_BLOCK_DATA(current_block) + pos, CLEAR_CHR,
 		       used_size - pos);
 	}
-	current_block->left = current_frame_block->block_space_used[frame_pos];
+	current_block->left = current_frame_block->block_space_left[frame_pos];
 	current_block->lowwater = current_block->left;
 
 	if (current_block->next != NULL) {