patch 9.0.0795: readblob() always reads the whole file
Problem: readblob() always reads the whole file.
Solution: Add arguments to read part of the file. (Ken Takata,
closes #11402)
diff --git a/src/blob.c b/src/blob.c
index a4e9981..92efb67 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -182,22 +182,52 @@
}
/*
- * Read "blob" from file "fd".
+ * Read blob from file "fd".
+ * Caller has allocated a blob in "rettv".
* Return OK or FAIL.
*/
int
-read_blob(FILE *fd, blob_T *blob)
+read_blob(FILE *fd, typval_T *rettv, off_T offset, off_T size_arg)
{
+ blob_T *blob = rettv->vval.v_blob;
struct stat st;
+ int whence;
+ off_T size = size_arg;
if (fstat(fileno(fd), &st) < 0)
+ return FAIL; // can't read the file, error
+
+ if (offset >= 0)
+ {
+ if (size == -1)
+ // size may become negative, checked below
+ size = st.st_size - offset;
+ whence = SEEK_SET;
+ }
+ else
+ {
+ if (size == -1)
+ size = -offset;
+ whence = SEEK_END;
+ }
+ // Trying to read bytes that aren't there results in an empty blob, not an
+ // error.
+ if (size < 0 || size > st.st_size)
+ return OK;
+ if (vim_fseek(fd, offset, whence) != 0)
+ return OK;
+
+ if (ga_grow(&blob->bv_ga, (int)size) == FAIL)
return FAIL;
- if (ga_grow(&blob->bv_ga, st.st_size) == FAIL)
- return FAIL;
- blob->bv_ga.ga_len = st.st_size;
+ blob->bv_ga.ga_len = (int)size;
if (fread(blob->bv_ga.ga_data, 1, blob->bv_ga.ga_len, fd)
< (size_t)blob->bv_ga.ga_len)
+ {
+ // An empty blob is returned on error.
+ blob_free(rettv->vval.v_blob);
+ rettv->vval.v_blob = NULL;
return FAIL;
+ }
return OK;
}
diff --git a/src/evalfunc.c b/src/evalfunc.c
index b769c08..8943a30 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -1078,6 +1078,7 @@
static argcheck_T arg3_string_any_string[] = {arg_string, NULL, arg_string};
static argcheck_T arg3_string_bool_bool[] = {arg_string, arg_bool, arg_bool};
static argcheck_T arg3_string_number_bool[] = {arg_string, arg_number, arg_bool};
+static argcheck_T arg3_string_number_number[] = {arg_string, arg_number, arg_number};
static argcheck_T arg3_string_or_dict_bool_dict[] = {arg_string_or_dict_any, arg_bool, arg_dict_any};
static argcheck_T arg3_string_string_bool[] = {arg_string, arg_string, arg_bool};
static argcheck_T arg3_string_string_dict[] = {arg_string, arg_string, arg_dict_any};
@@ -2339,7 +2340,7 @@
ret_number, f_rand},
{"range", 1, 3, FEARG_1, arg3_number,
ret_list_number, f_range},
- {"readblob", 1, 1, FEARG_1, arg1_string,
+ {"readblob", 1, 3, FEARG_1, arg3_string_number_number,
ret_blob, f_readblob},
{"readdir", 1, 3, FEARG_1, arg3_string_any_dict,
ret_list_string, f_readdir},
diff --git a/src/filepath.c b/src/filepath.c
index d9fe83a..023c732 100644
--- a/src/filepath.c
+++ b/src/filepath.c
@@ -1792,16 +1792,27 @@
long cnt = 0;
char_u *p; // position in buf
char_u *start; // start of current line
+ off_T offset = 0;
+ off_T size = -1;
if (argvars[1].v_type != VAR_UNKNOWN)
{
- if (STRCMP(tv_get_string(&argvars[1]), "b") == 0)
- binary = TRUE;
- if (STRCMP(tv_get_string(&argvars[1]), "B") == 0)
- blob = TRUE;
+ if (always_blob)
+ {
+ offset = (off_T)tv_get_number(&argvars[1]);
+ if (argvars[2].v_type != VAR_UNKNOWN)
+ size = (off_T)tv_get_number(&argvars[2]);
+ }
+ else
+ {
+ if (STRCMP(tv_get_string(&argvars[1]), "b") == 0)
+ binary = TRUE;
+ if (STRCMP(tv_get_string(&argvars[1]), "B") == 0)
+ blob = TRUE;
- if (argvars[2].v_type != VAR_UNKNOWN)
- maxline = (long)tv_get_number(&argvars[2]);
+ if (argvars[2].v_type != VAR_UNKNOWN)
+ maxline = (long)tv_get_number(&argvars[2]);
+ }
}
if ((blob ? rettv_blob_alloc(rettv) : rettv_list_alloc(rettv)) == FAIL)
@@ -1818,19 +1829,15 @@
}
if (*fname == NUL || (fd = mch_fopen((char *)fname, READBIN)) == NULL)
{
- semsg(_(e_cant_open_file_str), *fname == NUL ? (char_u *)_("<empty>") : fname);
+ semsg(_(e_cant_open_file_str),
+ *fname == NUL ? (char_u *)_("<empty>") : fname);
return;
}
if (blob)
{
- if (read_blob(fd, rettv->vval.v_blob) == FAIL)
- {
+ if (read_blob(fd, rettv, offset, size) == FAIL)
semsg(_(e_cant_read_file_str), fname);
- // An empty blob is returned on error.
- blob_free(rettv->vval.v_blob);
- rettv->vval.v_blob = NULL;
- }
fclose(fd);
return;
}
@@ -2007,7 +2014,11 @@
void
f_readblob(typval_T *argvars, typval_T *rettv)
{
- if (in_vim9script() && check_for_string_arg(argvars, 0) == FAIL)
+ if (in_vim9script()
+ && (check_for_string_arg(argvars, 0) == FAIL
+ || check_for_opt_number_arg(argvars, 1) == FAIL
+ || (argvars[1].v_type != VAR_UNKNOWN
+ && check_for_opt_number_arg(argvars, 2) == FAIL)))
return;
read_file_or_blob(argvars, rettv, TRUE);
diff --git a/src/proto/blob.pro b/src/proto/blob.pro
index 54e4a37..176f43e 100644
--- a/src/proto/blob.pro
+++ b/src/proto/blob.pro
@@ -10,7 +10,7 @@
void blob_set(blob_T *blob, int idx, int byte);
void blob_set_append(blob_T *blob, int idx, int byte);
int blob_equal(blob_T *b1, blob_T *b2);
-int read_blob(FILE *fd, blob_T *blob);
+int read_blob(FILE *fd, typval_T *rettv, off_T offset, off_T size);
int write_blob(FILE *fd, blob_T *blob);
char_u *blob2string(blob_T *blob, char_u **tofree, char_u *numbuf);
blob_T *string2blob(char_u *str);
diff --git a/src/testdir/test_blob.vim b/src/testdir/test_blob.vim
index ce8c3d0..a54cede 100644
--- a/src/testdir/test_blob.vim
+++ b/src/testdir/test_blob.vim
@@ -488,10 +488,29 @@
call writefile(b, 'Xblob')
VAR br = readfile('Xblob', 'B')
call assert_equal(b, br)
+ VAR br2 = readblob('Xblob')
+ call assert_equal(b, br2)
+ VAR br3 = readblob('Xblob', 1)
+ call assert_equal(b[1 :], br3)
+ VAR br4 = readblob('Xblob', 1, 2)
+ call assert_equal(b[1 : 2], br4)
+ VAR br5 = readblob('Xblob', -3)
+ call assert_equal(b[-3 :], br5)
+ VAR br6 = readblob('Xblob', -3, 2)
+ call assert_equal(b[-3 : -2], br6)
+
+ VAR br1e = readblob('Xblob', 10000)
+ call assert_equal(0z, br1e)
+ VAR br2e = readblob('Xblob', -10000)
+ call assert_equal(0z, br2e)
+
call delete('Xblob')
END
call v9.CheckLegacyAndVim9Success(lines)
+ call assert_fails("call readblob('notexist')", 'E484:')
+ " TODO: How do we test for the E485 error?
+
" This was crashing when calling readfile() with a directory.
call assert_fails("call readfile('.', 'B')", 'E17: "." is a directory')
endfunc
diff --git a/src/version.c b/src/version.c
index a143f0d..a5855b8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
static int included_patches[] =
{ /* Add new patch number below this line */
/**/
+ 795,
+/**/
794,
/**/
793,