Changed custom attribute descriptors to used arrays

While linked-lists do have some minor benefits, arrays are more
idiomatic in C and may provide a more intuitive API.

Initially the linked-list approach was more beneficial than it is now,
since it allowed custom attributes to be chained to internal linked
lists of attributes. However, this was dropped because exposing the
internal attribute list in this way created a rather messy user
interface that required strictly encoding the attributes with the
on-disk tag format.

Minor downside, users can no longer introduce custom attributes in
different layers (think OS vs app). Minor upside, the code size and
stack usage was reduced a bit.

Fortunately, this API can always be changed in the future without
breaking anything (except maybe API compatibility).
This commit is contained in:
Christopher Haster
2019-01-08 08:52:03 -06:00
parent 66d751544d
commit 51b2c7e4b6
3 changed files with 115 additions and 119 deletions

View File

@@ -156,10 +156,12 @@ TEST
echo "--- Set/get file attribute ---"
tests/test.py << TEST
lfs_mount(&lfs, &cfg) => 0;
struct lfs_attr a1 = {'A', buffer, 4};
struct lfs_attr b1 = {'B', buffer+4, 6, &a1};
struct lfs_attr c1 = {'C', buffer+10, 5, &b1};
struct lfs_file_config cfg1 = {.attrs = &c1};
struct lfs_attr attrs1[] = {
{'A', buffer, 4},
{'B', buffer+4, 6},
{'C', buffer+10, 5},
};
struct lfs_file_config cfg1 = {.attrs=attrs1, .attr_count=3};
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
memcpy(buffer, "aaaa", 4);
@@ -173,53 +175,55 @@ tests/test.py << TEST
memcmp(buffer+4, "bbbbbb", 6) => 0;
memcmp(buffer+10, "ccccc", 5) => 0;
b1.size = 0;
attrs1[1].size = 0;
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
lfs_file_close(&lfs, &file[0]) => 0;
memset(buffer, 0, 15);
b1.size = 6;
attrs1[1].size = 6;
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
lfs_file_close(&lfs, &file[0]) => 0;
memcmp(buffer, "aaaa", 4) => 0;
memcmp(buffer+4, "\0\0\0\0\0\0", 6) => 0;
memcmp(buffer+10, "ccccc", 5) => 0;
b1.size = 6;
attrs1[1].size = 6;
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
memcpy(buffer+4, "dddddd", 6);
lfs_file_close(&lfs, &file[0]) => 0;
memset(buffer, 0, 15);
b1.size = 6;
attrs1[1].size = 6;
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
lfs_file_close(&lfs, &file[0]) => 0;
memcmp(buffer, "aaaa", 4) => 0;
memcmp(buffer+4, "dddddd", 6) => 0;
memcmp(buffer+10, "ccccc", 5) => 0;
b1.size = 3;
attrs1[1].size = 3;
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
memcpy(buffer+4, "eee", 3);
lfs_file_close(&lfs, &file[0]) => 0;
memset(buffer, 0, 15);
b1.size = 6;
attrs1[1].size = 6;
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
lfs_file_close(&lfs, &file[0]) => 0;
memcmp(buffer, "aaaa", 4) => 0;
memcmp(buffer+4, "eee\0\0\0", 6) => 0;
memcmp(buffer+10, "ccccc", 5) => 0;
a1.size = LFS_ATTR_MAX+1;
attrs1[0].size = LFS_ATTR_MAX+1;
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_WRONLY, &cfg1)
=> LFS_ERR_NOSPC;
struct lfs_attr a2 = {'A', buffer, 4};
struct lfs_attr b2 = {'B', buffer+4, 9, &a2};
struct lfs_attr c2 = {'C', buffer+13, 5, &b2};
struct lfs_file_config cfg2 = {.attrs = &c2};
struct lfs_attr attrs2[] = {
{'A', buffer, 4},
{'B', buffer+4, 9},
{'C', buffer+13, 5},
};
struct lfs_file_config cfg2 = {.attrs=attrs2, .attr_count=3};
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_RDWR, &cfg2) => 0;
memcpy(buffer+4, "fffffffff", 9);
lfs_file_close(&lfs, &file[0]) => 0;
a1.size = 4;
attrs1[0].size = 4;
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
lfs_file_close(&lfs, &file[0]) => 0;
@@ -227,10 +231,12 @@ tests/test.py << TEST
TEST
tests/test.py << TEST
lfs_mount(&lfs, &cfg) => 0;
struct lfs_attr a2 = {'A', buffer, 4};
struct lfs_attr b2 = {'B', buffer+4, 9, &a2};
struct lfs_attr c2 = {'C', buffer+13, 5, &b2};
struct lfs_file_config cfg2 = {.attrs = &c2};
struct lfs_attr attrs2[] = {
{'A', buffer, 4},
{'B', buffer+4, 9},
{'C', buffer+13, 5},
};
struct lfs_file_config cfg2 = {.attrs=attrs2, .attr_count=3};
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_RDONLY, &cfg2) => 0;
lfs_file_close(&lfs, &file[0]) => 0;
@@ -248,10 +254,12 @@ TEST
echo "--- Deferred file attributes ---"
tests/test.py << TEST
lfs_mount(&lfs, &cfg) => 0;
struct lfs_attr a1 = {'B', "gggg", 4};
struct lfs_attr b1 = {'C', "", 0, &a1};
struct lfs_attr c1 = {'D', "hhhh", 4, &b1};
struct lfs_file_config cfg1 = {.attrs = &c1};
struct lfs_attr attrs1[] = {
{'B', "gggg", 4},
{'C', "", 0},
{'D', "hhhh", 4},
};
struct lfs_file_config cfg1 = {.attrs=attrs1, .attr_count=3};
lfs_file_opencfg(&lfs, &file[0], "hello/hello", LFS_O_WRONLY, &cfg1) => 0;