diff options
Diffstat (limited to 'src/spdk/lib/util/pipe.c')
| -rw-r--r-- | src/spdk/lib/util/pipe.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/src/spdk/lib/util/pipe.c b/src/spdk/lib/util/pipe.c new file mode 100644 index 000000000..1c640dd2e --- /dev/null +++ b/src/spdk/lib/util/pipe.c @@ -0,0 +1,246 @@ +/*- + * BSD LICENSE + * + * Copyright (c) Intel Corporation. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "spdk/pipe.h" +#include "spdk/util.h" + +struct spdk_pipe { + uint8_t *buf; + uint32_t sz; + + uint32_t write; + uint32_t read; +}; + +struct spdk_pipe * +spdk_pipe_create(void *buf, uint32_t sz) +{ + struct spdk_pipe *pipe; + + pipe = calloc(1, sizeof(*pipe)); + if (pipe == NULL) { + return NULL; + } + + pipe->buf = buf; + pipe->sz = sz; + + return pipe; +} + +void +spdk_pipe_destroy(struct spdk_pipe *pipe) +{ + free(pipe); +} + +int +spdk_pipe_writer_get_buffer(struct spdk_pipe *pipe, uint32_t requested_sz, struct iovec *iovs) +{ + uint32_t sz; + uint32_t read; + uint32_t write; + + read = pipe->read; + write = pipe->write; + + if (read <= write) { + requested_sz = spdk_min(requested_sz, ((read + pipe->sz) - write - 1)); + + sz = spdk_min(requested_sz, pipe->sz - write); + + iovs[0].iov_base = (sz == 0) ? NULL : (pipe->buf + write); + iovs[0].iov_len = sz; + + requested_sz -= sz; + + if (requested_sz > 0) { + sz = spdk_min(requested_sz, read); + + iovs[1].iov_base = (sz == 0) ? NULL : pipe->buf; + iovs[1].iov_len = sz; + } else { + iovs[1].iov_base = NULL; + iovs[1].iov_len = 0; + } + } else { + sz = spdk_min(requested_sz, read - write - 1); + + iovs[0].iov_base = (sz == 0) ? NULL : (pipe->buf + write); + iovs[0].iov_len = sz; + iovs[1].iov_base = NULL; + iovs[1].iov_len = 0; + } + + return iovs[0].iov_len + iovs[1].iov_len; +} + +int +spdk_pipe_writer_advance(struct spdk_pipe *pipe, uint32_t requested_sz) +{ + uint32_t sz; + uint32_t read; + uint32_t write; + + read = pipe->read; + write = pipe->write; + + if (requested_sz > pipe->sz - 1) { + return -EINVAL; + } + + if (read <= write) { + if (requested_sz > (read + pipe->sz) - write) { + return -EINVAL; + } + + sz = spdk_min(requested_sz, pipe->sz - write); + + write += sz; + if (write > pipe->sz - 1) { + write = 0; + } + requested_sz -= sz; + + if (requested_sz > 0) { + if (requested_sz >= read) { + return -EINVAL; + } + + write = requested_sz; + } + } else { + if (requested_sz > (read - write - 1)) { + return -EINVAL; + } + + write += requested_sz; + } + + pipe->write = write; + + return 0; +} + +uint32_t +spdk_pipe_reader_bytes_available(struct spdk_pipe *pipe) +{ + uint32_t read; + uint32_t write; + + read = pipe->read; + write = pipe->write; + + if (read <= write) { + return write - read; + } + + return (write + pipe->sz) - read; +} + +int +spdk_pipe_reader_get_buffer(struct spdk_pipe *pipe, uint32_t requested_sz, struct iovec *iovs) +{ + uint32_t sz; + uint32_t read; + uint32_t write; + + read = pipe->read; + write = pipe->write; + + if (read <= write) { + sz = spdk_min(requested_sz, write - read); + + iovs[0].iov_base = (sz == 0) ? NULL : (pipe->buf + read); + iovs[0].iov_len = sz; + iovs[1].iov_base = NULL; + iovs[1].iov_len = 0; + } else { + sz = spdk_min(requested_sz, pipe->sz - read); + + iovs[0].iov_base = (sz == 0) ? NULL : (pipe->buf + read); + iovs[0].iov_len = sz; + + requested_sz -= sz; + + if (requested_sz > 0) { + sz = spdk_min(requested_sz, write); + iovs[1].iov_base = (sz == 0) ? NULL : pipe->buf; + iovs[1].iov_len = sz; + } else { + iovs[1].iov_base = NULL; + iovs[1].iov_len = 0; + } + } + + return iovs[0].iov_len + iovs[1].iov_len; +} + +int +spdk_pipe_reader_advance(struct spdk_pipe *pipe, uint32_t requested_sz) +{ + uint32_t sz; + uint32_t read; + uint32_t write; + + read = pipe->read; + write = pipe->write; + + if (read <= write) { + if (requested_sz > (write - read)) { + return -EINVAL; + } + + read += requested_sz; + } else { + sz = spdk_min(requested_sz, pipe->sz - read); + + read += sz; + if (read > pipe->sz - 1) { + read = 0; + } + requested_sz -= sz; + + if (requested_sz > 0) { + if (requested_sz > write) { + return -EINVAL; + } + + read = requested_sz; + } + } + + pipe->read = read; + + return 0; +} |