From f2d75ac7dc58f5ea59b231be6b83fea939b43ab8 Mon Sep 17 00:00:00 2001 From: "Neal H. Walfield" Date: Wed, 2 Sep 2015 10:24:33 +0200 Subject: [PATCH] iobuf: Add the IOBUF_INPUT_TEMP type to improve input temp handling. * common/iobuf.h (enum iobuf_use): Add new member, IOBUF_INPUT_TEMP. * common/iobuf.c (iobuf_temp_with_content): Create the iobuf as an IOBUF_INPUT_TEMP, not an IOBUF_INPUT buffer. Assert that LENGTH == A->D.SIZE. (iobuf_push_filter2): If A is an IOBUF_INPUT_TEMP, then make the new filter an IOBUF_INPUT filter and set its buffer size to IOBUF_BUFFER_SIZE. (underflow): If A is an IOBUF_INPUT_TEMP, then just return EOF; don't remove already read data. (iobuf_seek): If A is an IOBUF_INPUT_TEMP, don't discard the buffered data. (iobuf_alloc): Allow USE == IOBUF_INPUT_TEMP. (pop_filter): Allow USE == IOBUF_INPUT_TEMP. (iobuf_peek): Allow USE == IOBUF_INPUT_TEMP. (iobuf_writebyte): Fail if USE == IOBUF_INPUT_TEMP. (iobuf_write): Fail if USE == IOBUF_INPUT_TEMP. (iobuf_writestr): Fail if USE == IOBUF_INPUT_TEMP. (iobuf_flush_temp): Fail if USE == IOBUF_INPUT_TEMP. -- Signed-off-by: Neal H. Walfield . Introduce a new iobuf type, IOBUF_INPUT_TEMP. Use this for the iobuf created by iobuf_temp_with_content instead of IOBUF_INPUT. This was necessary so that seeking and peeking correctly work on this type of iobuf. In particular, seeking didn't work because we discarded the buffered data and peeking didn't work because we discarded data which was already read, which made seeking later impossible. --- common/iobuf.c | 39 ++++++++++++++++++++++----------------- common/iobuf.h | 10 +++++++--- 2 files changed, 29 insertions(+), 20 deletions(-) diff --git a/common/iobuf.c b/common/iobuf.c index a6786b199..795ff11b1 100644 --- a/common/iobuf.c +++ b/common/iobuf.c @@ -1099,7 +1099,7 @@ iobuf_alloc (int use, size_t bufsize) iobuf_t a; static int number = 0; - assert (use == IOBUF_INPUT + assert (use == IOBUF_INPUT || use == IOBUF_INPUT_TEMP || use == IOBUF_OUTPUT || use == IOBUF_OUTPUT_TEMP); if (bufsize == 0) { @@ -1220,7 +1220,8 @@ iobuf_temp_with_content (const char *buffer, size_t length) iobuf_t a; int i; - a = iobuf_alloc (IOBUF_INPUT, length); + a = iobuf_alloc (IOBUF_INPUT_TEMP, length); + assert (length == a->d.size); /* memcpy (a->d.buf, buffer, length); */ for (i=0; i < length; i++) a->d.buf[i] = buffer[i]; @@ -1619,6 +1620,12 @@ iobuf_push_filter2 (iobuf_t a, size. */ a->d.size = IOBUF_BUFFER_SIZE; } + else if (a->use == IOBUF_INPUT_TEMP) + /* Same idea as above. */ + { + a->use = IOBUF_INPUT; + a->d.size = IOBUF_BUFFER_SIZE; + } /* The new filter (A) gets a new buffer. @@ -1678,7 +1685,7 @@ pop_filter (iobuf_t a, int (*f) (void *opaque, int control, if (DBG_IOBUF) log_debug ("iobuf-%d.%d: pop '%s'\n", a->no, a->subno, iobuf_desc (a)); - if (a->use == IOBUF_OUTPUT_TEMP) + if (a->use == IOBUF_INPUT_TEMP || a->use == IOBUF_OUTPUT_TEMP) { /* This should be the last filter in the pipeline. */ assert (! a->chain); @@ -1765,6 +1772,11 @@ underflow (iobuf_t a, int clear_pending_eof) (int) a->d.size, (int) (a->d.len - a->d.start), (int) (a->d.size - (a->d.len - a->d.start))); + if (a->use == IOBUF_INPUT_TEMP) + /* By definition, there isn't more data to read into the + buffer. */ + return -1; + assert (a->use == IOBUF_INPUT); /* If there is still some buffered data, then move it to the start @@ -2056,7 +2068,7 @@ iobuf_peek (iobuf_t a, byte * buf, unsigned buflen) int n = 0; assert (buflen > 0); - assert (a->use == IOBUF_INPUT); + assert (a->use == IOBUF_INPUT || a->use == IOBUF_INPUT_TEMP); if (buflen > a->d.size) /* We can't peek more than we can buffer. */ @@ -2097,7 +2109,7 @@ iobuf_writebyte (iobuf_t a, unsigned int c) { int rc; - if (a->use == IOBUF_INPUT) + if (a->use == IOBUF_INPUT || a->use == IOBUF_INPUT_TEMP) { log_bug ("iobuf_writebyte called on an input pipeline!\n"); return -1; @@ -2119,7 +2131,7 @@ iobuf_write (iobuf_t a, const void *buffer, unsigned int buflen) const unsigned char *buf = (const unsigned char *)buffer; int rc; - if (a->use == IOBUF_INPUT) + if (a->use == IOBUF_INPUT || a->use == IOBUF_INPUT_TEMP) { log_bug ("iobuf_write called on an input pipeline!\n"); return -1; @@ -2152,7 +2164,7 @@ iobuf_write (iobuf_t a, const void *buffer, unsigned int buflen) int iobuf_writestr (iobuf_t a, const char *buf) { - if (a->use == IOBUF_INPUT) + if (a->use == IOBUF_INPUT || a->use == IOBUF_INPUT_TEMP) { log_bug ("iobuf_writestr called on an input pipeline!\n"); return -1; @@ -2200,7 +2212,7 @@ iobuf_temp_to_buffer (iobuf_t a, byte * buffer, size_t buflen) void iobuf_flush_temp (iobuf_t temp) { - if (temp->use == IOBUF_INPUT) + if (temp->use == IOBUF_INPUT || temp->use == IOBUF_INPUT_TEMP) log_bug ("iobuf_writestr called on an input pipeline!\n"); while (temp->chain) pop_filter (temp, temp->filter, NULL); @@ -2379,10 +2391,9 @@ iobuf_seek (iobuf_t a, off_t newpos) return -1; } #endif + /* Discard the buffer it is not a temp stream. */ + a->d.len = 0; } - /* Discard the buffer it is not a temp stream. */ - if (a->use != IOBUF_OUTPUT_TEMP) - a->d.len = 0; a->d.start = 0; a->nbytes = 0; a->nlimit = 0; @@ -2409,10 +2420,6 @@ iobuf_seek (iobuf_t a, off_t newpos) } - - - - const char * iobuf_get_real_fname (iobuf_t a) { @@ -2430,7 +2437,6 @@ iobuf_get_real_fname (iobuf_t a) return NULL; } - const char * iobuf_get_fname (iobuf_t a) { @@ -2462,7 +2468,6 @@ iobuf_set_partial_block_mode (iobuf_t a, size_t len) { block_filter_ctx_t *ctx = xcalloc (1, sizeof *ctx); - assert (a->use == IOBUF_INPUT || a->use == IOBUF_OUTPUT); ctx->use = a->use; if (!len) { diff --git a/common/iobuf.h b/common/iobuf.h index b65ea60d7..bce6c3162 100644 --- a/common/iobuf.h +++ b/common/iobuf.h @@ -124,12 +124,15 @@ enum iobuf_use /* Pipeline is in input mode. The data flows from the end to the beginning. That is, when reading from the pipeline, the first filter gets its input from the second filter, etc. */ - IOBUF_INPUT=1, + IOBUF_INPUT, + /* Pipeline is in input mode. The last filter in the pipeline is + a temporary buffer from which the data is "read". */ + IOBUF_INPUT_TEMP, /* Pipeline is in output mode. The data flows from the beginning to the end. That is, when writing to the pipeline, the user writes to the first filter, which transforms the data and sends it to the second filter, etc. */ - IOBUF_OUTPUT=2, + IOBUF_OUTPUT, /* Pipeline is in output mode. The last filter in the pipeline is a temporary buffer that grows as necessary. */ IOBUF_OUTPUT_TEMP @@ -274,7 +277,8 @@ int iobuf_is_pipe_filename (const char *fname); create a new primary source or primary sink, i.e., the last filter in the pipeline. - USE is IOBUF_INPUT, IOBUF_OUTPUT or IOBUF_OUTPUT_TEMP. + USE is IOBUF_INPUT, IOBUF_INPUT_TEMP, IOBUF_OUTPUT or + IOBUF_OUTPUT_TEMP. BUFSIZE is the desired internal buffer size (that is, the size of the typical read / write request). */