From: Julien Desfossez <jdesfossez@efficios.com>
Date: Wed, 15 Aug 2012 21:32:01 +0000 (-0400)
Subject: Fix: add mmap_base_offset to ctf_stream_pos
X-Git-Tag: v1.0.0-rc5~26
X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=commitdiff_plain;h=474150688a81e2bc487aaa9932af6a0585e5fb79

Fix: add mmap_base_offset to ctf_stream_pos

When dealing with mmap traces, the whole trace buffer is mmapped in
babeltrace and we may need to read it one subbuffer at a time.
In order to do that, we need to keep a reference of the base of the
current subbuffer inside the mmap region.

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/formats/ctf/types/integer.c b/formats/ctf/types/integer.c
index 07c07be6..71ac0f44 100644
--- a/formats/ctf/types/integer.c
+++ b/formats/ctf/types/integer.c
@@ -223,20 +223,24 @@ int ctf_integer_read(struct stream_pos *ppos, struct definition *definition)
 
 	if (!integer_declaration->signedness) {
 		if (integer_declaration->byte_order == LITTLE_ENDIAN)
-			bt_bitfield_read_le(mmap_align_addr(pos->base_mma), unsigned long,
+			bt_bitfield_read_le(mmap_align_addr(pos->base_mma) +
+					pos->mmap_base_offset, unsigned long,
 				pos->offset, integer_declaration->len,
 				&integer_definition->value._unsigned);
 		else
-			bt_bitfield_read_be(mmap_align_addr(pos->base_mma), unsigned long,
+			bt_bitfield_read_be(mmap_align_addr(pos->base_mma) +
+					pos->mmap_base_offset, unsigned long,
 				pos->offset, integer_declaration->len,
 				&integer_definition->value._unsigned);
 	} else {
 		if (integer_declaration->byte_order == LITTLE_ENDIAN)
-			bt_bitfield_read_le(mmap_align_addr(pos->base_mma), unsigned long,
+			bt_bitfield_read_le(mmap_align_addr(pos->base_mma) +
+					pos->mmap_base_offset, unsigned long,
 				pos->offset, integer_declaration->len,
 				&integer_definition->value._signed);
 		else
-			bt_bitfield_read_be(mmap_align_addr(pos->base_mma), unsigned long,
+			bt_bitfield_read_be(mmap_align_addr(pos->base_mma) +
+					pos->mmap_base_offset, unsigned long,
 				pos->offset, integer_declaration->len,
 				&integer_definition->value._signed);
 	}
@@ -266,20 +270,24 @@ int ctf_integer_write(struct stream_pos *ppos, struct definition *definition)
 		goto end;
 	if (!integer_declaration->signedness) {
 		if (integer_declaration->byte_order == LITTLE_ENDIAN)
-			bt_bitfield_write_le(mmap_align_addr(pos->base_mma), unsigned long,
+			bt_bitfield_write_le(mmap_align_addr(pos->base_mma) +
+					pos->mmap_base_offset, unsigned long,
 				pos->offset, integer_declaration->len,
 				integer_definition->value._unsigned);
 		else
-			bt_bitfield_write_be(mmap_align_addr(pos->base_mma), unsigned long,
+			bt_bitfield_write_be(mmap_align_addr(pos->base_mma) +
+					pos->mmap_base_offset, unsigned long,
 				pos->offset, integer_declaration->len,
 				integer_definition->value._unsigned);
 	} else {
 		if (integer_declaration->byte_order == LITTLE_ENDIAN)
-			bt_bitfield_write_le(mmap_align_addr(pos->base_mma), unsigned long,
+			bt_bitfield_write_le(mmap_align_addr(pos->base_mma) +
+					pos->mmap_base_offset, unsigned long,
 				pos->offset, integer_declaration->len,
 				integer_definition->value._signed);
 		else
-			bt_bitfield_write_be(mmap_align_addr(pos->base_mma), unsigned long,
+			bt_bitfield_write_be(mmap_align_addr(pos->base_mma) +
+					pos->mmap_base_offset, unsigned long,
 				pos->offset, integer_declaration->len,
 				integer_definition->value._signed);
 	}
diff --git a/include/babeltrace/ctf/types.h b/include/babeltrace/ctf/types.h
index 43afaef7..94231555 100644
--- a/include/babeltrace/ctf/types.h
+++ b/include/babeltrace/ctf/types.h
@@ -59,6 +59,7 @@ struct ctf_stream_pos {
 
 	/* Current position */
 	off_t mmap_offset;	/* mmap offset in the file, in bytes */
+	off_t mmap_base_offset;	/* offset of start of packet in mmap, in bytes */
 	size_t packet_size;	/* current packet size, in bits */
 	size_t content_size;	/* current content size, in bits */
 	uint32_t *content_size_loc; /* pointer to current content size */
@@ -148,7 +149,8 @@ char *ctf_get_pos_addr(struct ctf_stream_pos *pos)
 {
 	/* Only makes sense to get the address after aligning on CHAR_BIT */
 	assert(!(pos->offset % CHAR_BIT));
-	return mmap_align_addr(pos->base_mma) + (pos->offset / CHAR_BIT);
+	return mmap_align_addr(pos->base_mma) +
+		pos->mmap_base_offset + (pos->offset / CHAR_BIT);
 }
 
 static inline