Mercurial > vim
changeset 30922:ed6acfafa17e v9.0.0795
patch 9.0.0795: readblob() always reads the whole file
Commit: https://github.com/vim/vim/commit/11df3aeee548b959ccd4b9a4d3c44651eab6b3ce
Author: K.Takata <kentkt@csc.jp>
Date: Wed Oct 19 14:02:40 2022 +0100
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)
| author | Bram Moolenaar <Bram@vim.org> |
|---|---|
| date | Wed, 19 Oct 2022 15:15:05 +0200 |
| parents | 546eac4f9926 |
| children | bbc069df8597 |
| files | runtime/doc/builtin.txt src/blob.c src/evalfunc.c src/filepath.c src/proto/blob.pro src/testdir/test_blob.vim src/version.c |
| diffstat | 7 files changed, 99 insertions(+), 24 deletions(-) [+] |
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--- a/runtime/doc/builtin.txt +++ b/runtime/doc/builtin.txt @@ -445,7 +445,8 @@ pyxeval({expr}) any evaluate |python_x rand([{expr}]) Number get pseudo-random number range({expr} [, {max} [, {stride}]]) List items from {expr} to {max} -readblob({fname}) Blob read a |Blob| from {fname} +readblob({fname} [, {offset} [, {size}]]) + Blob read a |Blob| from {fname} readdir({dir} [, {expr} [, {dict}]]) List file names in {dir} selected by {expr} readdirex({dir} [, {expr} [, {dict}]]) @@ -6847,10 +6848,21 @@ range({expr} [, {max} [, {stride}]]) GetExpr()->range() < -readblob({fname}) *readblob()* +readblob({fname} [, {offset} [, {size}]]) *readblob()* Read file {fname} in binary mode and return a |Blob|. + If {offset} is specified, read the file from the specified + offset. If it is a negative value, it is used as an offset + from the end of the file. E.g., to read the last 12 bytes: > + readblob('file.bin', -12) +< If {size} is specified, only the specified size will be read. + E.g. to read the first 100 bytes of a file: > + readblob('file.bin', 0, 100) +< If {size} is -1 or omitted, the whole data starting from + {offset} will be read. When the file can't be opened an error message is given and the result is an empty |Blob|. + When trying to read bytes beyond the end of the file the + result is an empty blob. Also see |readfile()| and |writefile()|.
--- a/src/blob.c +++ b/src/blob.c @@ -182,22 +182,52 @@ blob_equal( } /* - * 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; }
--- a/src/evalfunc.c +++ b/src/evalfunc.c @@ -1078,6 +1078,7 @@ static argcheck_T arg3_string_any_dict[] 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 @@ static funcentry_T global_functions[] = 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},
--- a/src/filepath.c +++ b/src/filepath.c @@ -1792,16 +1792,27 @@ read_file_or_blob(typval_T *argvars, typ 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 (argvars[2].v_type != VAR_UNKNOWN) - maxline = (long)tv_get_number(&argvars[2]); + 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 ((blob ? rettv_blob_alloc(rettv) : rettv_list_alloc(rettv)) == FAIL) @@ -1818,19 +1829,15 @@ read_file_or_blob(typval_T *argvars, typ } 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 @@ read_file_or_blob(typval_T *argvars, typ 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);
--- a/src/proto/blob.pro +++ b/src/proto/blob.pro @@ -10,7 +10,7 @@ int blob_get(blob_T *b, int idx); 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);
--- a/src/testdir/test_blob.vim +++ b/src/testdir/test_blob.vim @@ -488,10 +488,29 @@ func Test_blob_read_write() 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