From 8721846f8b03ca7aa1d592abd00a0c9a721e11c6 Mon Sep 17 00:00:00 2001
From: Vincent Dupont <vincent@otakeys.com>
Date: Mon, 17 Jul 2017 12:42:12 +0200
Subject: [PATCH] Constify pointer for write operations

---
 src/spiffs.h           |  6 +++---
 src/spiffs_cache.c     |  2 +-
 src/spiffs_hydrogen.c  | 10 +++++-----
 src/spiffs_nucleus.c   |  6 +++---
 src/spiffs_nucleus.h   | 18 ++++++++----------
 src/test/test_spiffs.c |  2 +-
 6 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/src/spiffs.h b/src/spiffs.h
index 534c3df..991aabf 100644
--- a/src/spiffs.h
+++ b/src/spiffs.h
@@ -84,7 +84,7 @@ struct spiffs_t;
 /* spi read call function type */
 typedef s32_t (*spiffs_read)(struct spiffs_t *fs, u32_t addr, u32_t size, u8_t *dst);
 /* spi write call function type */
-typedef s32_t (*spiffs_write)(struct spiffs_t *fs, u32_t addr, u32_t size, u8_t *src);
+typedef s32_t (*spiffs_write)(struct spiffs_t *fs, u32_t addr, u32_t size, const u8_t *src);
 /* spi erase call function type */
 typedef s32_t (*spiffs_erase)(struct spiffs_t *fs, u32_t addr, u32_t size);
 
@@ -93,7 +93,7 @@ typedef s32_t (*spiffs_erase)(struct spiffs_t *fs, u32_t addr, u32_t size);
 /* spi read call function type */
 typedef s32_t (*spiffs_read)(u32_t addr, u32_t size, u8_t *dst);
 /* spi write call function type */
-typedef s32_t (*spiffs_write)(u32_t addr, u32_t size, u8_t *src);
+typedef s32_t (*spiffs_write)(u32_t addr, u32_t size, const u8_t *src);
 /* spi erase call function type */
 typedef s32_t (*spiffs_erase)(u32_t addr, u32_t size);
 #endif // SPIFFS_HAL_CALLBACK_EXTRA
@@ -468,7 +468,7 @@ s32_t SPIFFS_read(spiffs *fs, spiffs_file fh, void *buf, s32_t len);
  * @param len           how much to write
  * @returns number of bytes written, or -1 if error
  */
-s32_t SPIFFS_write(spiffs *fs, spiffs_file fh, void *buf, s32_t len);
+s32_t SPIFFS_write(spiffs *fs, spiffs_file fh, const void *buf, s32_t len);
 
 /**
  * Moves the read/write file offset. Resulting offset is returned or negative if error.
diff --git a/src/spiffs_cache.c b/src/spiffs_cache.c
index 37c9d64..e28911d 100644
--- a/src/spiffs_cache.c
+++ b/src/spiffs_cache.c
@@ -185,7 +185,7 @@ s32_t spiffs_phys_wr(
     spiffs_file fh,
     u32_t addr,
     u32_t len,
-    u8_t *src) {
+    const u8_t *src) {
   (void)fh;
   spiffs_page_ix pix = SPIFFS_PADDR_TO_PAGE(fs, addr);
   spiffs_cache *cache = spiffs_get_cache(fs);
diff --git a/src/spiffs_hydrogen.c b/src/spiffs_hydrogen.c
index 69e0c22..1114f51 100644
--- a/src/spiffs_hydrogen.c
+++ b/src/spiffs_hydrogen.c
@@ -430,22 +430,22 @@ s32_t SPIFFS_read(spiffs *fs, spiffs_file fh, void *buf, s32_t len) {
 
 
 #if !SPIFFS_READ_ONLY
-static s32_t spiffs_hydro_write(spiffs *fs, spiffs_fd *fd, void *buf, u32_t offset, s32_t len) {
+static s32_t spiffs_hydro_write(spiffs *fs, spiffs_fd *fd, const void *buf, u32_t offset, s32_t len) {
   (void)fs;
   s32_t res = SPIFFS_OK;
   s32_t remaining = len;
   if (fd->size != SPIFFS_UNDEFINED_LEN && offset < fd->size) {
     s32_t m_len = MIN((s32_t)(fd->size - offset), len);
-    res = spiffs_object_modify(fd, offset, (u8_t *)buf, m_len);
+    res = spiffs_object_modify(fd, offset, buf, m_len);
     SPIFFS_CHECK_RES(res);
     remaining -= m_len;
-    u8_t *buf_8 = (u8_t *)buf;
+    const u8_t *buf_8 = buf;
     buf_8 += m_len;
     buf = buf_8;
     offset += m_len;
   }
   if (remaining > 0) {
-    res = spiffs_object_append(fd, offset, (u8_t *)buf, remaining);
+    res = spiffs_object_append(fd, offset, buf, remaining);
     SPIFFS_CHECK_RES(res);
   }
   return len;
@@ -453,7 +453,7 @@ static s32_t spiffs_hydro_write(spiffs *fs, spiffs_fd *fd, void *buf, u32_t offs
 }
 #endif // !SPIFFS_READ_ONLY
 
-s32_t SPIFFS_write(spiffs *fs, spiffs_file fh, void *buf, s32_t len) {
+s32_t SPIFFS_write(spiffs *fs, spiffs_file fh, const void *buf, s32_t len) {
   SPIFFS_API_DBG("%s "_SPIPRIfd " "_SPIPRIi "\n", __func__, fh, len);
 #if SPIFFS_READ_ONLY
   (void)fs; (void)fh; (void)buf; (void)len;
diff --git a/src/spiffs_nucleus.c b/src/spiffs_nucleus.c
index 12c9de8..301f179 100644
--- a/src/spiffs_nucleus.c
+++ b/src/spiffs_nucleus.c
@@ -754,7 +754,7 @@ s32_t spiffs_page_allocate_data(
     spiffs *fs,
     spiffs_obj_id obj_id,
     spiffs_page_header *ph,
-    u8_t *data,
+    const u8_t *data,
     u32_t len,
     u32_t page_offs,
     u8_t finalize,
@@ -1195,7 +1195,7 @@ s32_t spiffs_object_open_by_page(
 #if !SPIFFS_READ_ONLY
 // Append to object
 // keep current object index (header) page in fs->work buffer
-s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
+s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, const u8_t *data, u32_t len) {
   spiffs *fs = fd->fs;
   s32_t res = SPIFFS_OK;
   u32_t written = 0;
@@ -1442,7 +1442,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
 #if !SPIFFS_READ_ONLY
 // Modify object
 // keep current object index (header) page in fs->work buffer
-s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
+s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, const u8_t *data, u32_t len) {
   spiffs *fs = fd->fs;
   s32_t res = SPIFFS_OK;
   u32_t written = 0;
diff --git a/src/spiffs_nucleus.h b/src/spiffs_nucleus.h
index 3d77d50..7b89f01 100644
--- a/src/spiffs_nucleus.h
+++ b/src/spiffs_nucleus.h
@@ -545,7 +545,7 @@ s32_t spiffs_phys_wr(
 #endif
     u32_t addr,
     u32_t len,
-    u8_t *src);
+    const u8_t *src);
 
 s32_t spiffs_phys_cpy(
     spiffs *fs,
@@ -619,11 +619,10 @@ s32_t spiffs_obj_lu_find_id_and_span_by_phdr(
 
 // ---------------
 
-s32_t spiffs_page_allocate_data(
-    spiffs *fs,
+s32_t spiffs_page_allocate_data(spiffs *fs,
     spiffs_obj_id obj_id,
     spiffs_page_header *ph,
-    u8_t *data,
+    const u8_t *data,
     u32_t len,
     u32_t page_offs,
     u8_t finalize,
@@ -696,16 +695,15 @@ s32_t spiffs_object_open_by_page(
     spiffs_flags flags,
     spiffs_mode mode);
 
-s32_t spiffs_object_append(
-    spiffs_fd *fd,
+s32_t spiffs_object_append(spiffs_fd *fd,
     u32_t offset,
-    u8_t *data,
+    const u8_t *data,
     u32_t len);
 
 s32_t spiffs_object_modify(
     spiffs_fd *fd,
     u32_t offset,
-    u8_t *data,
+    const u8_t *data,
     u32_t len);
 
 s32_t spiffs_object_read(
@@ -807,8 +805,8 @@ s32_t spiffs_object_index_consistency_check(
 // checked in test builds, otherwise plain memcpy (unless already defined)
 #ifdef _SPIFFS_TEST
 #define _SPIFFS_MEMCPY(__d, __s, __l) do { \
-    intptr_t __a1 = (intptr_t)((u8_t*)(__s)); \
-    intptr_t __a2 = (intptr_t)((u8_t*)(__s)+(__l)); \
+    intptr_t __a1 = (intptr_t)((const u8_t*)(__s)); \
+    intptr_t __a2 = (intptr_t)((const u8_t*)(__s)+(__l)); \
     intptr_t __b1 = (intptr_t)((u8_t*)(__d)); \
     intptr_t __b2 = (intptr_t)((u8_t*)(__d)+(__l)); \
     if (__a1 <= __b2 && __b1 <= __a2) { \
diff --git a/src/test/test_spiffs.c b/src/test/test_spiffs.c
index 374028a..e96d4de 100644
--- a/src/test/test_spiffs.c
+++ b/src/test/test_spiffs.c
@@ -174,7 +174,7 @@ static s32_t _write(
 #if SPIFFS_HAL_CALLBACK_EXTRA
     spiffs *fs,
 #endif
-    u32_t addr, u32_t size, u8_t *src) {
+    u32_t addr, u32_t size, const u8_t *src) {
   int i;
   //printf("wr %08x %i\n", addr, size);
   if (log_flash_ops) {
-- 
2.11.0