Add readme content

.editorconfig

@@ -14,8 +14,8 @@ insert_final_newline = true
 [*.{c,h}]
 indent_style = tab
 
-# YAML files want space indentation
-[*.{yml}]
+# YAML, MD files want space indentation
+[*.{yml,md}]
 indent_style = space
 indent_size = 4
 

Makefile

@@ -1,7 +1,10 @@
 
 # Where are include/zlib.h and lib/libz.so installed?
 ZLIB_PATH = /usr
+ZLIB_INC_PATH = $(ZLIB_PATH)/include
+ZLIB_LIB_PATH = $(ZLIB_PATH)/lib
 
+# This should not require modification
 MODULE_big = gzip
 OBJS = pg_gzip.o
 EXTENSION = gzip
@@ -12,8 +15,8 @@ EXTRA_CLEAN =
 CURL_CONFIG = curl-config
 PG_CONFIG = pg_config
 
-CFLAGS += -I$(ZLIB_PATH)/include
-LIBS += -L$(ZLIB_PATH)/lib -lz
+CFLAGS += -I$(ZLIB_INC_PATH)/include
+LIBS += -L$(ZLIB_LIB_PATH)/lib -lz
 SHLIB_LINK := $(LIBS)
 
 ifdef DEBUG

README.md

@@ -1 +1,42 @@
-# pgsql-gzip
+# PostgreSQL GZIP/GUNZIP Functions
+
+[![Build Status](https://api.travis-ci.org/pramsey/pgsql-gzip.svg?branch=master)](https://travis-ci.org/pramsey/pgsql-gzip)
+
+## Motivation
+
+Sometimes you just need to compress your `bytea` object before you return it to the client.
+
+Sometimes you receive a compressed binary object from the client, and you have to uncompress it to do something useful.
+
+This extension is for that.
+
+## Examples
+
+    > SELECT gzip('this is my this is my this is my this is my text');
+
+                           gzip
+    --------------------------------------------------
+     \x789c2bc9c82c5600a2dc4a851282ccd48a1200a382112e
+
+
+    > SELECT encode(gunzip('\x789c2bc9c82c5600a2dc4a851282ccd48a1200a382112e'), 'escape')
+
+                          encode
+    --------------------------------------------------
+     this is my this is my this is my this is my text
+    (1 row)
+
+
+## Functions
+
+* `gzip(uncompressed BYTEA, [compression_level INTEGER])` returns `BYTEA`
+* `gunzip(compressed BYTEA)` returns `BYTEA`
+
+
+## Installation
+
+### UNIX
+
+If you have PostgreSQL devel packages and zlib installed, you should have `pg_config` on your path, so you should be able to just run `make`, then `make install`, then in your database `CREATE EXTENSION gzip`.
+
+If your `libz` is installed in a non-standard location, you may need to edit `ZLIB_PATH`.

pg_gzip.c

@@ -85,6 +85,9 @@ Datum pg_gzip(PG_FUNCTION_ARGS)
 	uint8 out[ZCHUNK];
 	bytea *compressed;
 
+	if (compression_level < -1 || compression_level > 9)
+		elog(ERROR, "invalid compression level: %d", compression_level);
+
 	initStringInfo(&si);
 
 	/* Prepare the z_stream state */