| BIO_s_mem.pod (1.1.1.4) | BIO_s_mem.pod (1.1.1.5) |
|---|---|
| 1=pod 2 3=head1 NAME 4 5BIO_s_secmem, 6BIO_s_mem, BIO_set_mem_eof_return, BIO_get_mem_data, BIO_set_mem_buf, 7BIO_get_mem_ptr, BIO_new_mem_buf - memory BIO 8 --- 45 unchanged lines hidden (view full) --- 54empty. If the B<v> is zero then an empty memory BIO will return EOF (that is 55it will return zero and BIO_should_retry(b) will be false. If B<v> is non 56zero then it will return B<v> when it is empty and it will set the read retry 57flag (that is BIO_read_retry(b) is true). To avoid ambiguity with a normal 58positive return value B<v> should be set to a negative value, typically -1. 59 60BIO_get_mem_data() sets *B<pp> to a pointer to the start of the memory BIOs data 61and returns the total amount of data available. It is implemented as a macro. | 1=pod 2 3=head1 NAME 4 5BIO_s_secmem, 6BIO_s_mem, BIO_set_mem_eof_return, BIO_get_mem_data, BIO_set_mem_buf, 7BIO_get_mem_ptr, BIO_new_mem_buf - memory BIO 8 --- 45 unchanged lines hidden (view full) --- 54empty. If the B<v> is zero then an empty memory BIO will return EOF (that is 55it will return zero and BIO_should_retry(b) will be false. If B<v> is non 56zero then it will return B<v> when it is empty and it will set the read retry 57flag (that is BIO_read_retry(b) is true). To avoid ambiguity with a normal 58positive return value B<v> should be set to a negative value, typically -1. 59 60BIO_get_mem_data() sets *B<pp> to a pointer to the start of the memory BIOs data 61and returns the total amount of data available. It is implemented as a macro. |
| 62Note the pointer returned by this call is informative, no transfer of ownership 63of this memory is implied. See notes on BIO_set_close(). |
|
| 62 63BIO_set_mem_buf() sets the internal BUF_MEM structure to B<bm> and sets the 64close flag to B<c>, that is B<c> should be either BIO_CLOSE or BIO_NOCLOSE. 65It is a macro. 66 67BIO_get_mem_ptr() places the underlying BUF_MEM structure in *B<pp>. It is 68a macro. 69 --- 39 unchanged lines hidden (view full) --- 109flag set can have unexpected outcome when the reads and writes to the 110BIO are intertwined. As documented above the BIO will be reset to the 111state after the last completed write operation. The effects of reads 112preceding that write operation cannot be undone. 113 114Calling BIO_get_mem_ptr() prior to a BIO_reset() call with 115BIO_FLAGS_NONCLEAR_RST set has the same effect as a write operation. 116 | 64 65BIO_set_mem_buf() sets the internal BUF_MEM structure to B<bm> and sets the 66close flag to B<c>, that is B<c> should be either BIO_CLOSE or BIO_NOCLOSE. 67It is a macro. 68 69BIO_get_mem_ptr() places the underlying BUF_MEM structure in *B<pp>. It is 70a macro. 71 --- 39 unchanged lines hidden (view full) --- 111flag set can have unexpected outcome when the reads and writes to the 112BIO are intertwined. As documented above the BIO will be reset to the 113state after the last completed write operation. The effects of reads 114preceding that write operation cannot be undone. 115 116Calling BIO_get_mem_ptr() prior to a BIO_reset() call with 117BIO_FLAGS_NONCLEAR_RST set has the same effect as a write operation. 118 |
| 119Calling BIO_set_close() with BIO_NOCLOSE orphans the BUF_MEM internal to the 120BIO, _not_ its actual data buffer. See the examples section for the proper 121method for claiming ownership of the data pointer for a deferred free operation. 122 |
|
| 117=head1 BUGS 118 119There should be an option to set the maximum size of a memory BIO. 120 121=head1 RETURN VALUES 122 123BIO_s_mem() and BIO_s_secmem() return a valid memory B<BIO_METHOD> structure. 124 --- 21 unchanged lines hidden (view full) --- 146Extract the BUF_MEM structure from a memory BIO and then free up the BIO: 147 148 BUF_MEM *bptr; 149 150 BIO_get_mem_ptr(mem, &bptr); 151 BIO_set_close(mem, BIO_NOCLOSE); /* So BIO_free() leaves BUF_MEM alone */ 152 BIO_free(mem); 153 | 123=head1 BUGS 124 125There should be an option to set the maximum size of a memory BIO. 126 127=head1 RETURN VALUES 128 129BIO_s_mem() and BIO_s_secmem() return a valid memory B<BIO_METHOD> structure. 130 --- 21 unchanged lines hidden (view full) --- 152Extract the BUF_MEM structure from a memory BIO and then free up the BIO: 153 154 BUF_MEM *bptr; 155 156 BIO_get_mem_ptr(mem, &bptr); 157 BIO_set_close(mem, BIO_NOCLOSE); /* So BIO_free() leaves BUF_MEM alone */ 158 BIO_free(mem); 159 |
| 160Extract the BUF_MEM ptr, claim ownership of the internal data and free the BIO 161and BUF_MEM structure: |
|
| 154 | 162 |
| 163 BUF_MEM *bptr; 164 char *data; 165 166 BIO_get_mem_data(bio, &data); 167 BIO_get_mem_ptr(bio, &bptr); 168 BIO_set_close(mem, BIO_NOCLOSE); /* So BIO_free orphans BUF_MEM */ 169 BIO_free(bio); 170 bptr->data = NULL; /* Tell BUF_MEM to orphan data */ 171 BUF_MEM_free(bptr); 172 ... 173 free(data); 174 |
|
| 155=head1 COPYRIGHT 156 | 175=head1 COPYRIGHT 176 |
| 157Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved. | 177Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved. |
| 158 159Licensed under the Apache License 2.0 (the "License"). You may not use 160this file except in compliance with the License. You can obtain a copy 161in the file LICENSE in the source distribution or at 162L<https://www.openssl.org/source/license.html>. 163 164=cut | 178 179Licensed under the Apache License 2.0 (the "License"). You may not use 180this file except in compliance with the License. You can obtain a copy 181in the file LICENSE in the source distribution or at 182L<https://www.openssl.org/source/license.html>. 183 184=cut |