On Thu, 3 Aug 2023 18:54:00 -0400
Stevie Alvarez <stevie.6strings@xxxxxxxxx> wrote:
> From: "Stevie Alvarez (Google)" <stevie.6strings@xxxxxxxxx>
>
> traceeval_init() creates a new struct traceeval instance with regards
> to the struct traceeval_type array arguments keys and vals. These arrays
> define the structure of the histogram, with each describing the expected
> structure of inserted arrays of union traceeval_data. The keys and vals
> arguments are copied on the heap to ensure that the struct traceeval
> instance has access to the definition regardless of how the user
> initialized keys and vals.
>
> Signed-off-by: Stevie Alvarez (Google) <stevie.6strings@xxxxxxxxx>
> ---
> Makefile | 2 +-
> include/traceeval-hist.h | 5 +
> src/Makefile | 1 +
> src/histograms.c | 223 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 230 insertions(+), 1 deletion(-)
> create mode 100644 src/histograms.c
>
> diff --git a/Makefile b/Makefile
> index 4a24d5a..3ea051c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -172,7 +172,7 @@ libs: $(LIBRARY_A) $(LIBRARY_SO)
>
> VALGRIND = $(shell which valgrind)
> UTEST_DIR = utest
> -UTEST_BINARY = trace-utest
> +UTEST_BINARY = eval-utest
This seems like it doesn't belong in this patch.
>
> test: force $(LIBRARY_STATIC)
> ifneq ($(CUNIT_INSTALLED),1)
> diff --git a/include/traceeval-hist.h b/include/traceeval-hist.h
> index 4664974..5bea025 100644
> --- a/include/traceeval-hist.h
> +++ b/include/traceeval-hist.h
> @@ -125,4 +125,9 @@ struct traceeval_iterator;
>
> struct traceeval;
>
> +/* Histogram interfaces */
> +
> +struct traceeval *traceeval_init(const struct traceeval_type *keys,
> + const struct traceeval_type *vals);
> +
> #endif /* __LIBTRACEEVAL_HIST_H__ */
> diff --git a/src/Makefile b/src/Makefile
> index b4b6e52..b32a389 100644
> --- a/src/Makefile
> +++ b/src/Makefile
> @@ -4,6 +4,7 @@ include $(src)/scripts/utils.mk
>
> OBJS =
> OBJS += trace-analysis.o
> +OBJS += histograms.o
>
> OBJS := $(OBJS:%.o=$(bdir)/%.o)
>
> diff --git a/src/histograms.c b/src/histograms.c
> new file mode 100644
> index 0000000..be17b89
> --- /dev/null
> +++ b/src/histograms.c
> @@ -0,0 +1,223 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * libtraceeval histogram interface implementation.
> + *
> + * Copyright (C) 2023 Google Inc, Stevie Alvarez <stevie.6strings@xxxxxxxxx>
> + */
> +
> +#include <stdbool.h>
> +#include <string.h>
> +#include <stdarg.h>
> +#include <stdio.h>
> +
> +#include <traceeval-hist.h>
> +
> +/* A key-value pair */
> +struct entry {
> + union traceeval_data *keys;
> + union traceeval_data *vals;
> +};
> +
> +/* A table of key-value entries */
> +struct hist_table {
> + struct entry *map;
> + size_t nr_entries;
> +};
> +
> +/* Histogram */
> +struct traceeval {
> + struct traceeval_type *key_types;
> + struct traceeval_type *val_types;
> + struct hist_table *hist;
> + size_t nr_key_types;
> + size_t nr_val_types;
> +};
> +
> +/* Iterate over results of histogram */
> +struct traceeval_iterator {};
Add the traceeval_iterator struct when it is used.
It's not relevant to this patch.
> +
> +/*
> + * print_err() - print an error message
> + * @fmt: String format
> + * @...: (optional) Additional arguments to print in conjunction with @format
> + */
> +static void print_err(const char *fmt, ...)
> +{
> + va_list ap;
> +
> + va_start(ap, fmt);
> + vfprintf(stderr, fmt, ap);
> + va_end(ap);
> + fprintf(stderr, "\n");
> +}
> +
> +/*
> + * type_release() - free a struct traceeval_type array
> + * @defs: The array to release
> + * @len: The length of @defs
> + *
> + * It is assumed that all elements of @defs, within the length of @len, have
> + * name fields initialized to valid pointers.
> + *
> + * This function was designed to be used on an array allocated by type_alloc().
> + * Note that type_alloc() initializes all name fields of elements within the
> + * returned size.
> + */
> +static void type_release(struct traceeval_type *defs, size_t len)
You added this but did not add traceeval_release().
traceeval_release() should be added in this patch to clean up everything
that traceeval_init() creates.
> +{
> + if (!defs)
> + return;
> +
> + for (size_t i = 0; i < len; i++) {
> + free(defs[i].name);
> + }
> +
> + free(defs);
> +}
> +
> +/*
> + * type_alloc() - clone a struct traceeval_type array
> + * @defs: The original array
> + * @copy: A pointer to where to place the @defs copy
> + *
> + * Clone traceeval_type array @defs to the heap, and place in @copy.
> + * @defs must be terminated with an instance of type TRACEEVAL_TYPE_NONE.
> + *
> + * The size of the copy pointed to by @copy is returned. It counts all elements
> + * in @defs excluding the terminating TRACEEVAL_TYPE_NONE traceeval_type.
> + * The copy contains everything from @defs excluding the TRACEEVAL_TYPE_NONE
> + * traceeval_type.
> + *
> + * The name field of each element of @defs (except for the terminating
> + * TRACEEVAL_TYPE_NONE) must be a NULL-terminated string. The validity of the
> + * name field is not checked, but errors are returned upon finding unset name
> + * fields and string duplication failures. It is guaranteed that all elements
> + * of the copy within the returned size have valid pointers in their name
> + * fields.
> + *
> + * Returns the size of the array pointed to by @copy, or, if an error occurs,
> + * the negative of the size of what's been allocated so far.
> + * If the return value is negative, the user is responsible for freeing
> + * -1 * return value number of elements from @copy.
> + */
> +static size_t type_alloc(const struct traceeval_type *defs,
> + struct traceeval_type **copy)
> +{
> + struct traceeval_type *new_defs = NULL;
> + size_t size;
> + size_t i;
> +
> + if (!defs) {
> + *copy = NULL;
> + return 0;
> + }
> +
> + for (size = 0; defs && defs[size].type != TRACEEVAL_TYPE_NONE; size++);
For loops like the above, please do:
for (size = 0; defs && defs[size].type != TRACEEVAL_TYPE_NONE; size++)
;
This makes it obvious that it's an empty loop and we don't think it's
looping over the line below it.
> +
> + if (size) {
> + new_defs = calloc(size, sizeof(*new_defs));
> + } else {
> + *copy = NULL;
> + return 0;
> + }
> +
> + for (i = 0; i < size; i++) {
> + /* copy current def data to new_def */
> + new_defs[i] = defs[i];
> +
> + /* copy name to heap, ensures name copied */
> + if (!defs[i].name)
> + goto fail_type_name;
No need to be so verbose in the labels.
goto fail;
is good enough ;-)
> + new_defs[i].name = strdup(defs[i].name);
> +
> + if (!new_defs[i].name)
> + goto fail_type_name;
> + }
> +
> + *copy = new_defs;
> + return size;
> +
> +fail_type_name:
> + if (defs[size].name)
> + print_err("failed to allocate name for traceeval_type %s", defs[size].name);
> + print_err("failed to allocate name for traceeval_type index %zu", size);
I would change the above to:
if (defs[i].name)
print_err("Failed to allocate traceveal_type %zu", size);
else
print_err("traceeval_type list missing a name");
> + *copy = new_defs;
> + return i * -1;
Also, we need to clean up here and not pass that info back to the caller.
// need to make i: ssize_t i;
for (; i >= 0; i--)
free(new_defs[i].name);
free(new_defs);
*copy = NULL;
return -1;
> +}
> +
> +/*
> + * traceeval_init - create a traceeval descriptor
> + * @keys: Defines the keys to differentiate traceeval entries
> + * @vals: Defines values attached to entries differentiated by @keys.
> + *
> + * The @keys and @vals define how the traceeval instance will be populated.
> + * The @keys will be used by traceeval_query() to find an instance within
> + * the "histogram". Note, both the @keys and @vals array must end with:
> + * { .type = TRACEEVAL_TYPE_NONE }.
> + *
> + * The @keys and @vals passed in are copied for internal use.
> + *
> + * For any member of @keys or @vals that isn't of type TRACEEVAL_TYPE_NONE,
> + * the name field must be a null-terminated string. For members of type
> + * TRACEEVAL_TYPE_NONE, the name is ignored.
> + *
> + * @vals can be NULL or start with its type field as TRACEEVAL_TYPE_NONE to
> + * define the values of the histogram to be empty.
> + * @keys must be populated with at least one element that is not
> + * TRACEEVAL_TYPE_NONE.
> + *
> + * Returns the descriptor on success, or NULL on error.
> + */
> +struct traceeval *traceeval_init(const struct traceeval_type *keys,
> + const struct traceeval_type *vals)
> +{
> + struct traceeval *teval;
> + char *err_msg;
> +
> + if (!keys)
> + return NULL;
> +
> + if (keys->type == TRACEEVAL_TYPE_NONE) {
> + err_msg = "keys cannot start with type TRACEEVAL_TYPE_NONE";
BTW, all the error messages should start with a capital letter.
"Keys cannot .."
> + goto fail_init_unalloced;
Just make this: goto fail;
> + }
> +
> + /* alloc teval */
> + teval = calloc(1, sizeof(*teval));
> + if (!teval) {
> + err_msg = "failed to allocate memory for traceeval instance";
> + goto fail_init_unalloced;
> + }
> +
> + /* alloc key types */
> + teval->nr_key_types = type_alloc(keys, &teval->key_types);
> + if (teval->nr_key_types <= 0) {
> + teval->nr_key_types *= -1;
Get rid of the above setting.
> + err_msg = "failed to allocate user defined keys";
> + goto fail_init;
and this: goto fail_release;
> + }
> +
> + /* alloc val types */
> + teval->nr_val_types = type_alloc(vals, &teval->val_types);
> + if (teval->nr_val_types < 0) {
> + teval->nr_val_types *= -1;
And git rid of the above too.
> + err_msg = "failed to allocate user defined values";
> + goto fail_init;
> + }
> +
> + /* alloc hist */
> + teval->hist = calloc(1, sizeof(*teval->hist));
> + if (!teval->hist) {
> + err_msg = "failed to allocate memory for histogram";
> + goto fail_init;
> + }
> +
> + return teval;
> +
> +fail_init:
> + traceeval_release(teval);
The above isn't defined. If you reference a function in a patch, it must be
at least defined.
> +
> +fail_init_unalloced:
> + print_err(err_msg);
> + return NULL;
> +}
-- Steve
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