HdrHistogram_c: 'C' port of High Dynamic Range (HDR) Histogram

HdrHistogram

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This port contains a subset of the functionality supported by the Java

implementation.  The current supported features are:

* Standard histogram with 64 bit counts (32/16 bit counts not supported)

* All iterator types (all values, recorded, percentiles, linear, logarithmic)

* Histogram serialisation (encoding version 1.2, decoding 1.0-1.2)

* Reader/writer phaser and interval recorder

Features not supported, but planned

* Auto-resizing of histograms

Features unlikely to be implemented

* Double histograms

* Atomic/Concurrent histograms

* 16/32 bit histograms

# Simple Tutorial

## Recording values

```C

#include <hdr_histogram.h>

struct hdr_histogram* histogram;

// Initialise the histogram

hdr_init(

    1,  // Minimum value

    INT64_C(3600000000),  // Maximum value

    3,  // Number of significant figures

    &histogram)  // Pointer to initialise

// Record value

hdr_record_value(

    histogram,  // Histogram to record to

    value)  // Value to record

// Record value n times

hdr_record_values(

    histogram,  // Histogram to record to

    value,  // Value to record

    10)  // Record value 10 times

// Record value with correction for co-ordinated omission.

hdr_record_corrected_value(

    histogram,  // Histogram to record to

    value,  // Value to record

    1000)  // Record with expected interval of 1000.

// Print out the values of the histogram

hdr_percentiles_print(

    histogram,

    stdout,  // File to write to

    5,  // Granularity of printed values

    1.0,  // Multiplier for results

    CLASSIC);  // Format CLASSIC/CSV supported.

```

## More examples

For more detailed examples of recording and logging results look at the

[hdr_decoder](examples/hdr_decoder.c)

and [hiccup](examples/hiccup.c)

examples.  You can run hiccup and decoder

and pipe the results of one into the other.

```

$ ./examples/hiccup | ./examples/hdr_decoder

```