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-rw-r--r--libnetdata/procfile/README.md49
1 files changed, 24 insertions, 25 deletions
diff --git a/libnetdata/procfile/README.md b/libnetdata/procfile/README.md
index 7037dc4ee..7487e6c63 100644
--- a/libnetdata/procfile/README.md
+++ b/libnetdata/procfile/README.md
@@ -1,4 +1,3 @@
-
# PROCFILE
procfile is a library for reading text data files (i.e `/proc` files) in the fastest possible way.
@@ -15,49 +14,49 @@ The library also supported quoted words (i.e. strings within of which the separa
Initially the caller:
-- calls `procfile_open()` to open the file and allocate the structures needed.
+- calls `procfile_open()` to open the file and allocate the structures needed.
### Iterations
For each iteration, the caller:
-- calls `procfile_readall()` to read updated contents.
- This call also rewinds (`lseek()` to 0) before reading it.
+- calls `procfile_readall()` to read updated contents.
+ This call also rewinds (`lseek()` to 0) before reading it.
+
+ For every file, a [BUFFER](../buffer/) is used that is automatically adjusted to fit
+ the entire file contents of the file. So the file is read with a single `read()` call
+ (providing atomicity / consistency when the data are read from the kernel).
+
+ Once the data are read, 2 arrays of pointers are updated:
- For every file, a [BUFFER](../buffer/) is used that is automatically adjusted to fit
- the entire file contents of the file. So the file is read with a single `read()` call
- (providing atomicity / consistency when the data are read from the kernel).
+ - a `words` array, pointing to each word in the data read
+ - a `lines` array, pointing to the first word for each line
- Once the data are read, 2 arrays of pointers are updated:
+ This is highly optimized. Both arrays are automatically adjusted to
+ fit all contents and are updated in a single pass on the data.
- - a `words` array, pointing to each word in the data read
- - a `lines` array, pointing to the first word for each line
+ The library provides a number of macros:
- This is highly optimized. Both arrays are automatically adjusted to
- fit all contents and are updated in a single pass on the data.
-
- The library provides a number of macros:
-
- - `procfile_lines()` returns the # of lines read
- - `procfile_linewords()` returns the # of words in the given line
- - `procfile_word()` returns a pointer the given word #
- - `procfile_line()` returns a pointer to the first word of the given line #
- - `procfile_lineword()` returns a pointer to the given word # of the given line #
+ - `procfile_lines()` returns the # of lines read
+ - `procfile_linewords()` returns the # of words in the given line
+ - `procfile_word()` returns a pointer the given word #
+ - `procfile_line()` returns a pointer to the first word of the given line #
+ - `procfile_lineword()` returns a pointer to the given word # of the given line #
### Cleanup
When the caller exits:
-- calls `procfile_free()` to close the file and free all memory used.
+- calls `procfile_free()` to close the file and free all memory used.
### Performance
-- a **raspberry Pi 1** (the oldest single core one) can process 5.000+ `/proc` files per second.
-- a **J1900 Celeron** processor can process 23.000+ `/proc` files per second per core.
+- a **raspberry Pi 1** (the oldest single core one) can process 5.000+ `/proc` files per second.
+- a **J1900 Celeron** processor can process 23.000+ `/proc` files per second per core.
To achieve this kind of performance, the library tries to work in batches so that the code
and the data are inside the processor's caches.
-This library is extensively used in netdata and its plugins.
+This library is extensively used in Netdata and its plugins.
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